Role of ABA and Components of the ABA Signalling Pathway

(1) Promotion of Developmental Processes, Prevention of Precocious Germination and Induction of Dormancy During Seed Development

Whether a seed is dormant or quiescent at maturity, its quality and vigour rely heavily on processes that occurred during seed development: reserve deposition (accumulation of storage proteins and storage lipids or starch), regulation of precocious germination, and development of stress tolerance. Control of seed maturation in turn is mediated by key interactions between different hormone signalling pathways and other regulatory cues provided by the seed environment.

Biometrics Applied to Molecular Analysis in Genetic Diversity

Studies about genetic diversity have been of great importance for the purposes of genetic improvement and to evaluate the impact of human activity on biodiversity. They are equally important in the understanding of the microevolutionary and macroevolutionary mechanisms that act in the diversification of the species, involving population studies, as well as in the optimization of the conservation of genetic diversity. They are also fundamental in understanding how natural populations are structured in time and space and the effects of anthropogenic activities on this structure and, consequently, on their chances of survival and/or extinction. This information provides an aid in finding the genetic losses generated by the isolation of the populations and of the individuals, which will be reflected in future generations, allowing for the establishment of better strategies to increase and preserve species diversity and diversity within the species.

Develop longer and stronger cotton fiber

The overwhelming majority of cotton harvested in the U.S. and worldwide is upland cotton, or Gossypium hirsutum, with more than 6.5 million acres planted in 2012 in Texas alone, according to the USDA. A higher-end cotton called Gossypium barbadense is more desirable because of greater fiber length and strength but is late-maturing, low-yielding and more difficult to grow because it requires dry climates with significant irrigation and is less resistant to pathogens and pests.

Benefits of Virus-Resistant Crops

Viral-resistance in crop plants is engineered based on the premise that the host plants express genes that interfere with the essential functions of the virus thereby upsetting the balance of related components. Coat-protein mediated pathogen-derived resistance is the commonly used method to introduce resistance in crop plants to viruses. In this approach, plants are transformed with a specific virus coat protein gene which interfere with critical processes such as replication, post-transcriptional gene expression, virion coating and uncoating and intercellular transport (Beachy et al., 1990; Kaniewski and Lawson, 1998). Constitutive expression of the coat protein gene confers protection against infection with the virus from which the gene is derived and possibly against infection from other related viruses (Di et al., 1996).

Commercially available virus-resistant crops include papaya, summer squash and potato. Virus-resistant papaya and squash have been available since 1998. Virus-resistant trait was stacked with Bt to broaden the range of protection against pest populations in potato and was discussed in insect-resistant plants section.

Adoption of virus-resistant papaya has been rapid since its introduction (53% in 2000). It is expected that virus-resistant papaya will be planted on almost 90% of the acreage in the next few years. On the other hand, biotechnology-derived summer squash was planted on less than 10% of the total acreage in the United States in 2000. Lack of resistance to important pathogenic viruses coupled with the availability of virus-resistance trait in only few varieties is cited to be the reasons for low adoption.

Biotechnology-derived virus-resistant crops are particularly valuable as management options that limit viral infestations to prevent serious yield losses are limited. Since viral infestations cannot be controlled by chemical means, conventional way to manage viruses is to manage their transmission by controlling insects. Preventing the spread of virus by controlling insect vectors is not effective for two reasons: virus transmission through insects is almost instantaneous which render insecticide applications futile and secondary hosts that harbour the viruses do not exhibit symptoms. Another widely used management technique to control viruses is use of resistant varieties in crops such as squash. Natural resistance may not be available to combat viruses in crops such as papaya. However, both these methods are not completely effective in preventing viral infestations.

Papaya industry in the United States concentrated mainly in Hawaii was on the brink of extinction in 1990s due to the epidemic infestations of papaya ringspot virus (PRSV). PRSV is the most important disease of papayas. The PRSV is transmitted by aphids and cannot be eradicated as secondary hosts harbour the virus without exhibiting any symptoms. Hawaiian farmers had no choice other than destroying the infested plants to contain the disease.

Viruses that limit summer squash production in the United States are zucchini mosaic virus (ZMV), watermelon mosaic virus 2 (WMV), cucumber mosaic virus (CMV) and papaya ringspot virus (PRSV). All these viruses are transmitted by aphids and affect a range of plants making it difficult and impossible to prevent virus infestations. Foliar applications of highly refined petroleum oil are widely used to serve as a barrier between aphid and the plant to prevent virus transmission. However, frequent applications are needed to ensure season-long protection.
Virus-resistant plants enable growers to reduce the use of pesticide by eliminating the need to spray insecticides to control the insects that transmit viral diseases, or herbicides to kill the weeds that harbour those insects. As a result, overall pesticide use and crop production costs have been reduced. An indirect benefit of virus-resistant crops is they do not serve as reservoirs for viruses unlike their conventional counterparts. As a result, further spread of virus to susceptible plants by vectors is prevented.

Papaya

Virus-resistant papaya is an exemplary example that demonstrated the promise biotechnology holds. It literally saved an industry that could disappear. A recent survey by USDA suggested that papaya yields increased by 33% in 2000 compared to 1998, which is a direct consequence of using PSRV-resistant plants (USDA-NASS, 2001b).

Squash

Biotechnology-derived virus protection in squash translated to increased number of harvests and increased yield per harvest. Evidence suggests that virus-resistant squash produces greater marketable yields of high quality fruit, particularly in production areas where high virus incidence limits the growing season both in terms of number of plantings and number of harvests per planting (Fuchs et al., 1998; Schultheis and Walters, 1998). However, virus-resistant squash has not reduced insecticide use as chemical applications that control aphids also control white flies and will be made to biotechnology-derived squash also.

Benefits of Insect-Resistant Bt Crops

Insect-resistant Bt crops offered positive benefits to growers in two ways: by reducing insecticide costs and increasing yields. Since Bt crops eliminate the need for insecticide applications, major impact of insect-resistant crops has been the reduction in insecticide use targeted for key pest control. Insect-resistant crops express toxic proteins during much of the crop season as a result of which supplemental insecticide applications are not needed for pest control. Unlike herbicide-tolerant crops, insect-resistant crops increased crop yields due to enhanced levels of insect control. Overall, direct grower benefits from insect-resistant Bt corn, cotton, potato and sweet corn were reported to be $112 million in 1999 in the United States (EPA, 2000). By 2001, net income of US growers was reported to increase by $228 million from Bt corn and cotton plantings alone (Gianessi et al., 2002).

Corn

A primary benefit of insect-resistant corn has been the opportunity to control a pest that previously escaped control and reduced yields. Though modest, adoption of Bt corn led to reductions in insecticide use. Since the introduction of Bt corn, acreage sprayed with insecticides for ECB control has been reduced resulting in over one million fewer acres treated for ECB (Carpenter and Gianessi, 2001). Only a minor acreage, about 5%, is treated for ECB control in the United States, which is the reason for the modest reduction in insecticide use due to Bt corn (Phipps and Park, 2002). Additionally, the insecticides used against the ECB are also used to control other insect pests to which Bt trait does not provide resistance and would still be applied regardless of ECB.

Yield gain and economic benefit from Bt-corn fluctuates based on variability in ECB infestation levels. While yield increased and resulting economic benefits were lower in low infestation years, Bt-corn delivered a significant economic benefit when ECB outbreaks occurred (Alstad et al., 1997). As a result, net returns have been higher for Bt corn in spite of seed premium and technology fees (Fernandez-Cornejo and McBride, 2000). On an average, yield advantage from Bt-corn ranged from 4% to 8%, depending on the levels of ECB infestation (Marra et al., 1998).

A significant benefit of Bt-corn is decreased secondary pathogen infestations (e.g. ear rot) due to reduction in entryways left by ECB (Alstad, 1997). Fusarium ear rot is the most common ear rot disease in the corn belt; it has been found in nearly every corn field at harvest. The severity of this disease is usually low, but it can reduce yield and quality. Symptoms of Fusarium ear rot are often highly correlated with ear damage by ECB. The primary importance of this disease is its association with mycotoxins, particularly the fumonisins. Fumonisins are a group of mycotoxins that can be fatal to livestock and are probable human carcinogens (Munkvold and Desjardin, 1997). The importance of fumonisins in human health is still a subject of debate, but there is evidence that they have some impact on cancer incidence (Marasas, 1995). Multi-year studies showed that kernel feeding by insects, extent of ear rot infestation and fumonisin levels in Bt corn were significantly lower than conventional corn (Munkvold et al., 1999). Volunteer corn in the following season has been reduced, as ears dropped due to ECB infestation are less with Bt corn (Alstad, 1997).

Depending on the prevalence of ECB populations, Bt-corn influences the local ECB population (Alstad, 1997; Andow and Hutchison, 1998). It is possible that planting non-Bt-corn near Bt-corn could suppress ECB populations in non-Bt corn and this localised benefit is called the halo effect. Similar effects may be noted with other insect-resistant crops.

Cotton

Insect-resistant Bt cotton has provided a tool to cotton growers to control the most damaging pests. Insect-resistant cotton resulted in highest per acre grower benefits and largest reduction in insecticide use among all the insect-resistant crops. In states such as Alabama, growers used the least amount of insecticides on cotton since the 1940s (Smith, 1997). A 1999 estimate by the EPA (2000) suggested a reduction of 1.6 million pounds of insecticide active ingredient use and 7.5 million acre treatments due to Bt cotton. Based on the USDA pesticide use data, growers in six major cotton-growing states reduced insecticide use by 16% and insecticide applications by 25% in 2000 compared to 1995 (Carpenter and Gianessi, 2002). A similar estimate by Fernandez-Cornejo and McBride (2000) also showed that Bt cotton growers applied 2.5 fewer insecticide applications per acre. Though not as dramatic as reductions in insecticide use, insect-resistant cotton led to reduced yield losses as a result of which yield advantage has been realised in many cotton-growing states (Fernandez-Cornejo and McBride, 2000). The overall effect of reduction in insecticide use and gains in yields has been higher net return to cotton growers, despite the technology fee. Grower benefits have increased from 16 million in 1996 to 44 million in 1999 due to Bt cotton (EPA, 2000).

By targeting specific insects through the naturally occurring protein in the plant, Bt cotton reduces the need for and use of chemical insecticides. By eliminating chemical sprays, the beneficial insects that naturally inhabit agricultural fields are maintained and can even provide a secondary level of pest control. This is the reason why Bt cotton adoption is high in areas where boll weevil eradication programmes are in effect as insurance against unchecked bollworm and budworm populations due to elimination of natural predators with the use of malathion.

Evidence states that insect-resistant crops impact local ecosystems favourably. Beneficial insect-feeding bird populations have been reported to be higher in numbers in Bt cotton fields compared to conventional fields (Edge et al., 2001).

A major worry concerning the success of Bt crops, especially cotton, is the potential vulnerability to eventual adaptation by insect pests to Bt toxin. Large-scale deployment of Bt crops will impose selection pressure for pre-existing Bt-resistant insects to increase their numbers resulting in the loss of viability of this environmentally sound pest control practice. Several resistance management strategies have been proposed to slow the evolution of insect adaptation to Bt genes such as refuges, intense field monitoring of insect-resistant plants for potential escapes and alternate control strategies.

To slow the adaptation of insects to Bt toxin, the EPA has mandated that cotton growers should plant at least 4% of their biotechnology-derived crop with conventional cotton varieties and this refuge cannot be treated with any insecticides. The advantage of planting refuges is that they will harbour susceptible insects and thus retard the evolution of insect resistance against the Bt gene. Gould et al., (1997) predicted that Bt cotton could remain efficacious for 10 years with 4% refuge.

Potato

Due to low adoption rates, insecticide use reductions in potato are not as dramatic as in cotton. Based on 4% market share of Bt potato, insecticide use reduction from Bt potato has been reported to be 89 000 less acre treatments with corresponding grower benefit of $9.30 (EPA, 2000) to $11.50 (Gianessi et al., 2002) per acre. Insect-resistant Bt potato has not yet made a significant impact on overall yield.

An indirect benefit of insect-resistant crops, potato and cotton in particular, is the worker safety the technology affords. Insecticides routinely used for pest control in cotton and potato such as organophosphates, carbamates and synthetic pyrethroids are known to cause adverse health effects in workers. Insect-resistant Bt cotton eliminates the need for the use of the above chemicals as a result of which occupational risk is minimised.

Sweet Corn

A notable impact of Bt sweet corn is the reduction in number of insecticide applications. Based on sweet corn acreage planted with Bt varieties in 1999, EPA (2000) reported that reduction in insecticide applications have been 4.3 per acre or a total of 127 000 acre applications in the United States. Reduction in insecticide applications on a per acre basis has been the highest in Bt sweet corn compared to any biotechnology-derived crop. Benefits from improved pest control and reduced application costs have been $5.40 per acre (EPA, 2000). An added benefit to insect-resistant sweet corn is the reduction in yield loss caused by feeding damage of fall armyworm and corn earworm. Season long protection offered by Bt sweet corn resulted in significantly higher marketable yield than conventional varieties (Stegelin, 2000). Overall, once the market penetration of Bt sweet corn increases, growers are expected to note significant reductions in overall insecticide use and enhanced returns.

Map of Plant Protein Interactions

An international team of scientists has described their mapping and early analyses of thousands of protein-to-protein interactions within the cells of Arabidopsis thaliana -- a variety of mustard plant that is to plant biology what the lab mouse is to human biology.

"With this one study we managed to double the plant protein-interaction data that are available to scientists," says Salk Institute plant biologist Joseph Ecker, a professor in the Plant Molecular and Cellular Biology Laboratory. "These data along with data from future 'interactome' mapping studies like this one should enable biologists to make agricultural plants more resistant to drought and diseases, more nutritious, and generally more useful to mankind."

The four-year project was funded by an $8 million National Science Foundation grant, and was headed by Marc Vidal, Pascal Braun, David Hill and colleagues at the Dana Farber Cancer Institute in Boston; and Ecker at the Salk Institute. "It was a natural collaboration," says Vidal, "because Joe and his colleagues at the Salk Institute had already sequenced the Arabidopsis genome and had cloned many of the protein-coding genes, whereas on our side at the Dana Farber Institute we had experience in making these protein interaction maps for other organisms such as yeast."

In the initial stages of the project, members of Ecker's lab led by research technician Mary Galli converted most of their accumulated library of Arabidopsis protein-coding gene clones into a form useful for protein-interaction tests. "For this project, over 10,000 'open reading frame' clones were converted and sequence verified in preparation for protein-interaction screening," says Galli.

Vidal, Braun, Hill and their colleagues systematically ran these open reading frames through a high quality protein-interaction screening process, based on a test known as the yeast two-hybrid screen. Out of more than forty million possible pair combinations, they found a total of 6,205 Arabidopsis protein- protein interactions, involving 2,774 individual proteins. The researchers confirmed the high quality of these data, for example by showing their overlap with protein interaction datafrom past studies.

The new map of 6,205 protein partnerings represents only about two percent of the full protein- protein "interactome" for Arabidopsis, since the screening test covered only a third of all Arabidopsis proteins, and wasn't sensitive enough to detect many weaker protein interactions. "There will be larger maps after this one," says Ecker.

Even as a preliminary step, though, the new map is clearly useful. The researchers were able to sort the protein interaction pairs they found into functional groups, revealing networks and "communities" of proteins that work together. "There had been very little information, for example, on how plant hormone signaling pathways communicate with one another," says Ecker. "But in this study we were able to find a number of intriguing links between these pathways."

A further analysis of their map provided new insight into plant evolution. Ecker and colleagues Arabidopsis genome data, reported a decade ago, had revealed that plants randomly duplicate their genes to a much greater extent than animals do. These gene duplication events apparently give plants some of the genetic versatility they need to stay adapted to shifting environments. In this study, the researchers found 1900 pairs of their mapped proteins that appeared to be the products of ancient gene-duplication events.

Using advanced genomic dating techniques, the researchers were able to gauge the span of time since each of these gene-duplication events -- the longest span being 700 million years -- and compare it with the changes in the two proteins' interaction partners. "This provides a measure of how evolution has rewired the functions of these proteins," says Vidal. "Our large, high-quality dataset and the naturally high frequency of these gene duplications in Arabidopsis allowed us to make such an analysis for the first time."

The researchers found evidence that the Arabidopsis protein partnerships tend to change quickly after the duplication event, then more slowly as the duplicated gene settles into its new function and is held there by evolutionary pressure. "Even though the divergence of these proteins' amino-acid sequences may continue, the divergence in terms of their respective partners slows drastically after a rapid initial change, which we hadn't expected to see," Vidal says.

In the July 29 issue of Science researchers from the Arabidopsis interactome mapping study reported yet another demonstration of the usefulness of their approach. Led by Jeffery L. Dangl of the University of North Carolina at Chapel Hill, they examined Arabidopsis protein interactions with the bacterium Pseudomonas syringae (Psy) and a fungus-like microbe called Hyaloperonospora arabidopsidis (Hpa). "Even though these two pathogens are separated by about a billion years of evolution, it turns out that the 'effector' proteins they use to subvert Arabidopsis cells during infection are both targeted against the same set of highly connected Arabidopsis proteins," says Ecker. "We looked at some of these targeted Arabidopsis proteins and found evidence that they serve as 'hubs' or control points for the plant immune system and related systems."

Ecker and his colleagues hope that these studies mark the start of a period of rapid advancement in understanding plant biology, and in putting that knowledge to use for human benefit. "This starts to give us a big, systems-level picture of how Arabidopsis works, and much of that systems-level picture is going to be relevant to -- and guide further research on -- other plant species, including those used in human agriculture and even pharmaceuticals,"Ecker says.

The "Arabidopsis Interactome Mapping Consortium" consists of over 20 national and international laboratories that contribute to this study with support from a number of funding agencies including the National Science Foundation and the National Institutes of Health.

Gene Mapping, DNA Marker-Aided Breeding and Genetic Transformation in Africa

It appears very likely that DNA marker-assisted breeding for a range of traits—particularly to control diseases and pests, and overcome abiotic stresses—is the second most important application of agrobiotechnology in the mid-term in Africa. Once biosafety laws and appropriate regulatory frameworks and systems are enacted in order to ensure food safety and minimise human health risks and environmental hazards, transgenic crops can be added to the tool-kit of plant breeders working in that region.

The International Center for Agricultural Research in Dry Areas (ICARDA) began operations in Aleppo, Syria, in 1977. The ICARDA mandate covered dry areas in West Asia and North Africa (WANA). The WANA region includes the primary centres of diversity of the ICARDA-mandated crop species: barley, lentils and broad beans (global mandate), and wheat, chickpea and a number of forage species [regional mandate, in collaboration with the International Maize and Wheat Improvement Center (CIMMYT) for wheat and the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) for chickpea].

In the ICARDA Medium-Term Plan for 1990–94, it was stated that, although food self-sufficiency would prove impossible during the 20th century in the WANA region, self-reliance for food should be enhanced through a combination of new technology, better farm practices, more favourable government policies and a more rational land-use pattern. While acknowledging that major increase in food production would come from lowlands with over 350 mm of rainfall annually, ICARDA focused its work on the highlands and driest areas.

A strategy has been developed for integrating biotechnologies into the ICARDA crop-enhancement activities, with a view of providing the National Agricultural Research Systems with well-targeted biotic and abiotic stress-tolerant cultivars and genetic stocks, through the evaluation, adaptation and application of novel genome analysis techniques (DNA marker technology). This approach is applied to crops as well as to the corresponding pathogens, viruses and pests, and should ultimately lead to a more efficient and effective use of existing genetic variability in the ICARDA-mandated crops. Genome analysis also allows for a better estimation of the diversity in these crops, and helps to improve management of the germplasm collections. In cases where insufficient genetic variability exists in the cultivated gene pool, wide crossing with the help of tissue-culture techniques is being explored to bridge species barriers. Double haploid techniques are used to achieve, in a short time, the homozygous state of segregants for fast trait evaluation and selection. Double haploid lines are also considered a useful material for DNA-marker linkage analysis. This strategy was incorporated within ICARDA's Medium-Term Plan for 1994–98 (Sasson, 2000).

While genetic transformation of broad bean (Vicia faba) is difficult to achieve, producing herbicide-resistant broad bean would allow the farmers to better control the invasion of their fields by the Orobanchae weeds (Baum et al., 2002).

With respect to chickpea (Cicer arietinum), genetic transformation aims at producing lines resistant to the blight caused by Ascochyta. Chickpea is cultivated on 11 247 723 ha (FAO Statistics, 1998) worldwide and its production reaches 8 829 095 tons, the average yield being 785 kg/ha. The yield range is 500 kg/ha (Algeria) to 1 800 kg/ha (Egypt). The Ascochyta blight is the most devastating disease of chickpea; the fungal pathogen is highly variable, at least three to six races have been identified; there are limited genetic resources for resistance in the chickpea gene-pool. Fertile transgenic Kabuli-/desi-type chickpea lines have been obtained by the ICARDA scientists, using Agrobacterium-mediated transformation of decapitated zygotic embryos and npt-II/pat as selectable markers. Other genetic constructs will be introduced, followed by the assessment of the resistance to the blight by the GM lines (Baum et al., 2002).

Fertile transgenic lentil (Lens culinaris) lines have also been obtained at ICARDA, using a transformation system developed at the Cooperative Research Centre (CRC) for Mediterranean Agriculture (CLIMA, based in Western Australia) and transferred to the WANA region (Baum et al., 2002).

Wide crossing in wheat and barley has been carried out in collaboration with the University of Cordoba, Spain. The transfer of desirable genes from wild species of Aegilops was carried out at ICARDA as well as in collaboration with the University of Tuscia, Viterbo. Interspecific and intergeneric hybridisation in winter cereals aims to transfer genes of abiotic stress tolerance such as drought, cold, heat and salinity from wild types to cultivated forms by expanding the genetic base against diseases, improving the quality and total biomass of Triticum and Hordeum in moisture-stressed areas and providing specific genetic stocks to national programmes for use in their breeding programmes (Sasson, 2000).

In the case of barley and wheat, following anther culture, inter-specific crosses and embryo rescue, the first double haploid lines were tested under field conditions by the early 1990s. The bulbosum technique was used for this purpose. Hordeum bulbosum is a wild barley species found throughout WANA; it can be crossed with wheat and barley (for barley only in the diploid form); however, after crossing, the bulbosum chromosomes are eliminated and the young embryo is cultured to produce haploids. After selection against biotic and abiotic stresses, double haploids are produced. These techniques could skip a number of intermediary breeding generations (Sasson, 2000).

An ovule-embryo rescue technique has been developed in order to cross the cultivated lentil species, Lens culinaris, with Lens nigricans, a wild species adapted to dry environments (Sasson, 2000).

With cooperation of the institutions involved in the North American Barley Genome Mapping Network Project, ICARDA is developing RFLP markers for barley breeding in low-rainfall environments. This would allow a more efficient and accurate selection of drought-tolerant barley germplasm. Drought tolerance is not a single trait, but the collective result of many traits of a plant which interact with each other positively or negatively. RFLP markers could be used for the identification and selection of single-gene traits associated with drought tolerance (such as osmotic adjustment, photoperiodic response in wheat, water-use efficiency). These were the main findings of a technical study carried out at the request of the Dutch Government's Directorate General for International Cooperation. Another project supported by the German Agency for Technical Cooperation (GTZ) aims to develop molecular markers (RFLP and RAPD/PCR) for barley breeding, in order to effectively select disease-resistant barley germplasm (Sasson, 2000).

The Centre d'étude regional pour l'amélioration de l'adaptation à la sécheresse (CERAAS, Regional Centre for Studies on the Improvement of Plant Adaptation to Drought) was set up in 1982 as a partnership between the Institut sénégalais de recherches agricoles (ISRA, Senegalese Institute for Agricultural Research, Dakar, Senegal), the French CIRAD and Universities of Paris VII and XII, with a view of improving and/or stabilising groundnut production in Senegal. In 1987, the Conference of African Agricultural Research Executives for West and Central Africa (CORAF/WECARD) made CERAAS a regional centre under its umbrella. Nowadays, CERAAS receives funds from the European Commission, other development investors and staff secondment from CIRAD.

CERAAS' general objective is to develop crop cultivars adapted to drought and provide methods of analysis and decision-making tools which will improve agricultural production in arid and semi-arid zones. CERAAS researchers are investigating the mechanisms which allow cowpea (Vigna unguiculata) to adapt to drought and they are trying to map the genes associated with this trait. They are also in the process of mapping cowpea population segregating for drought tolerance with the aim of identifying genetic markers associated with this trait. Micro-satellite markers are being used for this research (Ortiz, 2002).

Among CERAAS' development products, it is worth citing the following:

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Creation, in collaboration with the Senegalese Institute for Agricultural Research (ISRA), of a new groundnut variety with a very short life cycle, GC 8-35; this variety will eventually replace the oil-producing variety 55-437, and cultivated in Senegal on about 130 000 ha; the increase in yield estimated for one growing season will reimburse the investments made in research work conducted over 15 years for creating the new variety.
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Selection, in collaboration with ISRA, of about 30 groundnut varieties potentially more interesting than varieties GC 8-35 and 55-437 in terms of their production and their drought-resistance capacity; from this improved germplasm, several countries (Burkina Faso, Botswana and Brazil) have selected lines whose agronomic and physiological response to drought are superior to those of local varieties.
*
Creation and registration of eight sorghum varieties of agricultural importance in Mali, which often cover up to 95% of the area cultivated with sorghum; one of them, Migsor 86-30-03, is particularly resistant to drought and beating down by the wind; it is also used as a genitor in Africa and the USA.
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Development of a plant model (AraBHy), coupled with a geographic information system (GIS), that allows the estimation of groundnut production 1 month before harvest; initially developed for groundnut, this model can be adapted to pearl millet, cowpea and soybean, and to other environments, as has been done in Argentina. At the country level, this tool can considerably reduce the costs of identifying agricultural calamity zones and, therefore, contribute to a more effective management of food security.

The IITA (Ibadan, Nigeria), a CGIAR Future Harvest Center, through its Strategic Plan (2001–10), aims at targeting donors' investments to stimulate innovations (e.g., agrobiotechnology) needed to alleviate rural poverty, protect the environment and other natural resources, empower rural peoples and promote economic growth. More specifically, IITA conducts biotechnological research to address the food and income needs of sub-Saharan African countries. Priority is given to genetic transformation of cowpea and plantains/bananas; cassava and maize are a second priority. Molecular mapping of important genes associated with conventional breeding aims at enhancing tolerance or resistance to stresses, e.g. cassava mosaic disease, plant parasitic nematodes or the witchweed Striga. Priority is also given to DNA marker-assisted selection of plantain/banana, cassava and cowpea, whereas cocoa, maize and yams, in which DNA maps are also available, are second tier crops. IITA may also benefit from research advances in the genomics of soybeans, a major legume, also a model crop system. Gene discovery and cloning of functional DNA elements such as promoters will provide non-proprietary tools needed for genetic transformation.

IITA transfers, where appropriate and in collaboration with overseas partners and within the continent, biotechnological products from the laboratory to the market. One well-known example is micropropagation and clonal multiplication of vegetatively propagated crops. Another example is the assistance provided to the emerging private sector to use DNA fingerprinting of cultivars to protect proprietary rights, or to use molecular mapping for identifying new genes relevant to end-user needs.

IITA serves as a platform for technology transfer between overseas advanced research institutes and sub-Saharan African countries. By the end of 2002, 10 internationally-recruited staff were working on biotechnology at IITA laboratories in Cotonou (Benin), Ibadan (Nigeria), Namulonge (Uganda) and Yaounde (Cameroon), as well as at the high throughput genomics laboratory of the International Livestock Research Institute (ILRI) in Nairobi.

Finally, IITA enhances the capacity of national selected partners in order to apply and monitor biotechnology, e.g. IITA, together with research-for-development partners and development investors, is working towards the approval of biosafety guidelines concerning GMOs, as has been achieved in Nigeria (Ortiz, 2001).

Partnerships with African researchers are reinforced through group and individual training. For instance, with funding from the USDA and USAID, IITA initiated a project for developing and updating skills of biotechnologists from Nigeria and Ghana to address farmers' needs. This project deals with biotechnological capacity building and research, adapts available approaches for developing or strengthening bioinformatics databases; and conducts research on potential risks associated with the introduction of transgenic crops into Africa (Ortiz, 2002b).

In 2002, a visiting scientist assessed the status of, and needs for agrobiotechnology in West and Central Africa (thanks to a USAID grant given to IITA). This assessment will lead to the design of a regional agrobiotechnology programme for West and Central Africa. In the last quarter of 2002, IITA initiated, as implementing agency, the Nigerian Biotechnology Programme with an agenda driven by the Nigerian stakeholders and funding from the USAID and the Nigerian Government. This programme includes capacity building on genetic transformation—including testing biosafety guidelines, crop genomics and livestock biotechnology, as well as creating unbiased public awareness of biotechnology in Nigeria (Ortiz, 2002b).

Genetically Modified Crops in Developing Countries

By early 2003, genetically modified (genetically enhanced, as qualified by many scientists in developing countries) crops were already established in the third world: two-thirds of the 5.5 million farmers growing these crops are in developing countries, which demonstrates that small and poor farmers are also involved. In addition to maize, soybeans, rapeseed (canola) and a few horticultural crop varieties, genetically modified cotton is the fastest spreading non-food GM crop. It is currently cultivated in India, China, Indonesia, Thailand, Argentina and South Africa, and the prospects are very promising.

Illustrative regional examples of GM crops are given in later chapters. From the strategic viewpoint, the adoption of GM crops by an increasing number of developing countries, and particularly by the larger ones (e.g. China, India, Argentina), reflects the need to acquire the relevant technologies before they are completely in the hands of the industrialised countries. It also reflects the will to participate in the so-called biotechnology revolution and even to become formidable competitors in some areas, instead of just purchasing and adapting biotechnologies. China's huge commitment to plant biotechnology, through increasing five-fold the funds devoted to this area of endeavour (US $500 million annually by 2005) is illustrative of this trend.

Another key element in the strategy of developing countries is to improve their competitiveness in international commodity and agricultural product markets. For those who are big exporters and whose agriculture is not subsidised, GM crops and agricultural biotechnology can contribute to decreasing production costs (e.g. through the reduction of use of biocides) and to increasing farmers' incomes. This aspect has been clearly demonstrated for GM soybeans in Argentina and GM cotton in South Africa and China.

This strategy also requires the design and update of biosafety regulations, the establishment or revision of intellectual property legislation and active participation in the negotiations on trade-related issues at the World Trade Organization.

Adopting GM crops is not synonymous with exclusion of other forms of agriculture, particularly the so-called biological or organic agriculture. A number of developing countries, e.g. Argentina and Chile, have an important and prosperous organic agriculture sector, which they wish to preserve and even extend because of its commercial benefits (e.g. Chile exports high volumes of ‘organic’ products to Japan and the European Union). Nevertheless, the advantages offered by GM crops enable developing countries to meet more rapidly the need to establish higher yielding, stress- and pest-resistant crop varieties, particularly when one has to deal with pathogens and pests against which there is no known natural resistance or tolerance.

Naturally, the developing countries are carefully following the controversy on GM crops in the European Union member countries as well as the disaccord between those countries and the USA in this respect. They are vigilant at the World Trade Organization, the Codex Alimentarius Commission on GM organisms and their impact on health and nutrition, in order to safeguard their interests. They generally consider that agricultural biotechnology and GM crops can help them to face the challenges of sustainable agricultural development. In this respect, their position is not far from that of the representatives of farmers in industrialised countries who welcome these technologies and maintain the highest standards of biosafety and biovigilance. They also consider, to a large extent, that the precautionary principle (now called the precautionary approach, since the 2002 Earth Summit in Johannesburg) should not become a dogma that hampers research, trials and large-scale cultivation. They agree on the need for biovigilance as in the case of medicines.

With regard to labelling and traceability of GM or biotechnology-derived products, developing countries tend to refer to substantial equivalence of these products compared to conventional ones, and to adopt labelling when there are substantial differences in composition. Thus, sugar, starch or vegetable oils derived from GM crops should not be labelled as GM. They are pragmatic in discussing the minimum percentage of GMOs in foodstuffs and agricultural products, the threshold of 0.9% (proposed by the European Union's Council of Ministers) being considered as unrealistic.

Finally, developing countries support the strengthening of regulatory institutions and biosafety measures, but they wish to avoid over-regulation, which will hinder their competitiveness. There is also a growing trend of improving public perception and social acceptance of agricultural biotechnology in developing countries, involving the participation of all sectors of society.
Confronted by the urgent need to feed their people and make their agriculture more competitive on international commodity markets, the developing countries, be they food exporters or not, have resisted the adoption of a moratorium on the cultivation of GM crops like that in Europe. In contrast, they wish to draw benefits from modern agricultural biotechnology and seize the opportunities offered to them.

In addition to the competitive edge provided to the commodity-exporting developing countries, agricultural biotechnology must reach resource-poor farmers—a large majority in developing countries. For such a purpose, it is necessary to carry out the social analysis of these technologies, when they are transferred to the farming communities. It is also necessary to pay great attention to the so-called orphan crops such as sorghum, millet, cassava, yams, sweet potato, etc., which do not attract the big seed corporations, but which play a vital role in local and national economies.

While favouring a sustainable diversified agriculture, including agricultural biotechnology, and making special efforts to help the resource-poor farmers, developing countries can protect their biological diversity (e.g. through the conservation of potentially useful varieties), clone crops on a large scale and participate in the selection of new varieties with the appropriate traits. Many projects being carried out in developing countries reflect these goals, while at the same time key issues, such as biosafety regulation, risk assessment and management, intellectual property rights and training of human resources are dealt with.

There are undoubtedly, in this vast area of research and development, opportunities for collaboration among the developing countries but also between them and industrialised countries' public research centres, enterprises and professional associations. In this regard, we are dealing not only with solidarity, but also with mutually beneficial cooperation in important international markets.

IRRI Create Golden Rice to Overcome Vitamin A Deficiency

To help address the devastating impacts of vitamin A deficiency, particularly on the poor in Asia, the International Rice Research Institute (IRRI) and its national and international partners are now developing Golden Rice – a new type of rice that contains a source of vitamin A.

Vitamin A and human health

Vitamin A is an essential micronutrient that helps the body to fight diseases and maintain healthy eyesight. Vitamin A deficiency lowers immune system function, causing people to get sick more often and have a higher risk of dying from infections. Vitamin A deficiency can also cause night blindness and is a leading cause of preventable blindness in children.

Vitamin A deficiency particularly affects infants, young children, and women who are pregnant or nursing. According to the World Health Organization (WHO), an estimated 250,000 to 500,000 vitamin A-deficient children become blind every year, half of them dying within 12 months of losing their sight. With adequate vitamin A, young children are up to 30 percent less likely to die from infections and the death rate for women during or shortly after pregnancy can be reduced by approximately 40 percent.

Vitamin A deficiency can be reduced by eating more foods that are naturally high in vitamin A or beta-carotene (a form of vitamin A), by eating foods that have had these micronutrients added to them, or by taking supplements.
Vitamin A deficiency in rice-consuming populations

Vitamin A deficiency can be particularly severe in countries where the staple food contains no forms of vitamin A and other nutritious food is scarce, unavailable, or too expensive.

Rice is the staple food crop for more than half of the world’s population, and is especially important in Asia, where more than 60% of the world’s 1 billion poorest live. Rice is an affordable and filling food, yet it contains no source of vitamin A. More than 90 million children in Southeast Asia suffer from vitamin A deficiency, more than in any other region.
Golden Rice

Golden Rice is a type of rice that contains beneficial amounts of beta-carotene, which is used by the human body to make vitamin A. Beta-carotene gives Golden Rice its yellow color. Many fruits and vegetables, such as papaya and carrots, also get their color from beta-carotene. Golden Rice was bred using a combination of genetic modification and other breeding methods. It contains genes from maize and other sources that together produce beta-carotene. Golden Rice is expected to taste the same as other rice, be cooked in the same way, and have the same eating quality of other popular rice varieties.

According to research published in the American Journal of Clinical Nutrition, one cup of Golden Rice could supply half of the vitamin A needed every day. Golden Rice could be used in combination with existing ways of overcoming vitamin A deficiency through diet, fortification, and supplements.

Researchers have already found that the body turns more than 25% of the beta-carotene in Golden Rice into vitamin A, a better conversion rate than for many green, leafy vegetables.
Developing Golden Rice

Work to develop Golden Rice currently includes laboratory, greenhouse, and field studies at IRRI, national agricultural research institutions, and other institutions around the world to

* breed Golden Rice varieties that are well suited for different rice-growing environments and consumer preferences in Asia,
* confirm the nutritional benefits of Golden Rice in combating Vitamin A deficiency, and
* evaluate the safety of Golden Rice.

This research on Golden Rice will ensure that any approved Golden Rice varieties will grow just like other rice crops, with comparable yields and pest resistance, and with the same environmental impacts. It is expected that Golden Rice will be planted, harvested, threshed, and milled like current rice varieties.
All Golden Rice research is conducted according to national biosafety regulations and additional biosafety conditions established by the institutes carrying out the research.
IRRI’s role

IRRI coordinates the Golden Rice Network and works with national agricultural research institutes and other partners with expertise in agriculture and nutrition to research and develop Golden Rice. IRRI’s support for partners includes initial breeding of the Golden Rice trait into selected varieties, which involves laboratory work, greenhouse tests, and some preliminary field evaluation. These advanced breeding lines are being transferred to national partners for further development and assessment.

IRRI also works with national partners to

* provide technical support and training to help with breeding and development and build scientific capacity at the national level,
* help develop locally adapted plans to deliver Golden Rice to farmers and consumers, and
* research and collate biosafety data.

National partners

National agricultural research institutes in Bangladesh, China, India, Indonesia, the Philippines, and Vietnam are leading their in-country development of Golden Rice. They manage varietal development and selection, do field evaluations, and undertake biosafety research for science-based regulatory review of Golden Rice in the country. National partners will also interact with other public- and private-sector institutions and government to advance the release and adoption of Golden Rice by farmers and consumers.
Availability of Golden Rice

Golden Rice will be available to farmers and consumers only after it has been authorized by the agricultural, environmental, health, and food safety agencies of their countries. Public health officials, nongovernment organizations, grain traders, and private industry will be consulted in each country before Golden Rice is introduced.

Golden Rice may be approved in the Philippines and Bangladesh as early as 2013 and 2015, respectively, and introduced to the public in those countries soon after. Other countries developing Golden Rice in local varieties are India, Indonesia, and Vietnam.

Golden Rice will be made available to people with vitamin A deficiency in different ways depending on community needs and preferences.

Golden Rice will cost no more than other rice for farmers and consumers.
Funding for Golden Rice

Because of its enormous potential to benefit public health, the technology behind Golden Rice has been donated by its inventors, Professor Ingo Potrykus and Dr. Peter Beyer, for use by public institutions. Different governments and private charities are supporting the development and testing costs.

A one-time investment to develop a biofortified crop such as Golden Rice can generate new varieties for farmers to grow for years to come, in many different countries. There will be some recurrent expenditure for monitoring and maintaining the high beta-carotene trait in Golden Rice, but these costs will be relatively low compared with the ongoing costs of traditional supplementation and fortification programs.

Soource: http://irri.org

Adoption of GM Crops in The Future

The experience of the past is often the best guide for the future. The experience of the first seven years, 1996–2002, during which a cumulative total of over 235 million hectares (over 580 million acres) of transgenic crops were planted globally in 19 countries, has confirmed that the early promise of biotechnology has been fulfilled. GM crops can deliver substantial agronomic, environmental, economic and social benefits to farmers and, increasingly, to society at large. GM crops have met the expectations of large and small farmers planting transgenic crops in both industrial and developing countries.

The most compelling case for biotechnology, and more specifically GM crops is their capability to contribute to increasing crop productivity, particularly in the developing countries (James, 2002a, 2002b; www.isaaa.org; Pinstrup-Andersen and Schioler, 2001) where they can make a crucial contribution to food, feed and fibre security; conserving biodiversity, as a land-saving technology capable of higher productivity; more efficient use of external inputs and thus a more sustainable agriculture and environment; increasing stability of production to lessen the suffering during famines due to abiotic and biotic stresses; and improve economic and social benefits and the alleviation of abject poverty in developing countries (James, 2002b; UNDP, 2001). It is critical that a combination of conventional and biotechnology applications be adopted as the technology component of a global food, feed and fibre security strategy that also addresses other critical issues including population control and improved food, feed and fibre distribution. Adoption of such a strategy will allow society to continue to benefit from the vital contribution that plant breeding offers the global population.

With significant progress in the first seven years of the first decade, 1996–2005, when GM crops are being commercialised, what can we expect during the remaining three years, 2003–2005, at the dawn of a new era in crop biotechnology? The latest GM crop indicators for 2003 and beyond augur well for the future of crop biotechnology. In 2002, coincidental with increased political, policy and institutional support for GM crops, due to their acknowledged essential contribution to global food security, the global area of transgenic crops in 2002 benefited from continued growth of 12%. The number of farmers who benefited from GM crops in 2002 was approximately six million of which five million were resource-poor farmers planting Bt cotton, mainly in eight provinces in China and also in the Makathini Flats in the KwaZulu Natal province in South Africa (Ismael et al., 2002). The well-documented experience of China with Bt cotton (Huang et al., 2002, Pray et al., 2001, 2002) presents a remarkable case study where five million small resource-poor farmers in 2002 already benefited from significant agronomic, environmental, health and economic advantages—this is a unique example of how biotechnology can impact on poverty alleviation as advocated in the 2001 UNDP Human Development Report (UNDP, 2001). The China experience with Bt cotton lends itself for introduction and replication to carefully selected developing countries in Asia, Latin America and Africa where resource-poor farmers can learn, share and benefit from the rich experience of China—the majority of the hectarage of global cotton is in the developing countries of the world. Following a successful launch of Bt cotton by Indonesia in 2001, India, the largest cotton-growing country in the world, grew Bt cotton for the first time in 2002.

The opportunities and constraints associated with public acceptance of transgenic crops continue to be important challenges facing the global community. Because of our thrice-daily dependency on food, agriculture touches the life of every individual in the global community of over six billion. Unlike industrial countries, such as the United States and countries of the European Union, with few exceptions, all developing countries are net importers rather than exporters of food, and where a high percentage of the population employed in agriculture are either small resource-poor farmers practising subsistence farming or the rural landless who are dependent on agriculture for survival; 70% of the world's 1.3 billion poorest people are rural people, the majority of them are resource-poor farmers and their families. Agricultural employment, as a percentage of total employment, was 80% in the developing countries in 1950, and is still projected to be 50% in 2010 when the population of the developing countries will be approximately six billion, equivalent to the global population of today. Improved food, feed and fibre crops derived from appropriate conventional and biotechnology applications for small resource-poor farmers are vital for increasing productivity and income to provide access to food in the rural areas where the majority of the poverty, hunger and malnutrition exists. Crops are not only the principal source of food but are also the livelihood of farmers and agricultural workers. Increased crop productivity provides more employment and acts as the engine of economic growth in the rural communities. Producing more food, feed and fibre on small resource-poor subsistence farms, where most of it is consumed, has the significant advantage that the inevitable infrastructure constraints associated with transport can, to a large extent, be circumvented in that the produce is largely consumed at the same locations where it is produced.

Global society must seek equitable solutions that meet the different needs of people and nations and respect differing opinions regarding GM crops. Implementing an equitable policy is a challenge in a world where globalisation, a web of international protocols and international trade are all impacting on the ability of sovereign nations in the developing world to access and utilise biotechnology and GM crops in their national food, feed and fibre security strategies, to meet domestic and export needs. This does not imply that biotechnology and GM crops are panaceas. Biotechnology, like any other technology, has strengths and weaknesses and needs to be managed responsibly and effectively. Biotechnology represents one essential link in a long and complex chain that must be in place to develop and deliver more productive crops, which are urgently required by small resource-poor farmers in developing countries. This will require the political will, goodwill and unfailing support of both the public and private sectors in the industrial and developing countries to work together in harmony, as pledged during the 2002 World Summit on Sustainable Development in Johannesburg.

The Challenge of Global, Food, Feed and Fibre Security

The global population reached six billion on 12 October 1999, and is expected to reach nine billion by 2050, when approximately 90% of the world's population will live, or survive, in the three continents of the South: Asia, Africa and Latin America where today malnutrition results in 24 000 deaths per day. Thus, in the next 50 years, the population will increase by 50%, or three billion, and food production will need to be doubled on the same area of arable land (1.5 billion hectares), by 2050. The magnitude of the challenge of feeding tomorrow's world is difficult to conceive and the enormity of the task is probably best captured by the statement that: ‘In the next fifty years mankind will consume twice as much food as mankind has consumed since the beginning of agriculture, 10 000 years ago’ (James, 2002a, 2002b).

Crops are the major source of food globally. There is a widely held view in the international scientific and development community that conventional crop improvement alone will not allow us to meet the global food demands of 2050. What is being advocated is a global strategy that integrates both conventional crop improvement and biotechnology, including transgenic crops, which are often referred to as genetically modified (GM) crops; adoption of such a strategy would allow society to harness and optimise the contribution of biotechnology and GM crops to global food security. There is cautious optimism that such a strategy would contribute significantly to the alleviation of poverty and malnutrition which afflict 1.3 billion people and 815 million people, respectively, today, and that the global food demands of 2050 and beyond can be met.

China was the first country to commercialise transgenic crops in the early 1990s. The first approval for commercial sale of a genetically modified product for food use in an industrialised country was in the United States in 1994, but significant commercialisation did not actually begin until 1996. The unprecedented rapid adoption of transgenic crops during the initial seven-year period, 1996–2002 (Figure 63.1), when GM crops were first adopted, reflects the significant multiple benefits realised by large and small farmers in the industrial and developing countries that have grown transgenic crops commercially. Between 1996 and 2002, a total of 19 countries, 10 industrial and 9 developing, contributed to a more than 35-fold increase in the global area of transgenic crops from 1.7 million hectares in 1996 to 58.7 million hectares in 2002 (James, 2002a). The accumulated area of transgenic crops planted globally in the seven-year period, 1996–2002, totals more than 235 million hectares, equivalent to more than 575 million acres, an area equivalent to 25% of the land area of China or the United States, and 10 times greater than the land area of the UK.

In 2002, the global area of transgenic crops continued to grow for the sixth consecutive year at a sustained rate of growth of more than 10% between 2001 and 2002. The estimated global area of transgenic or GM crops for 2002 was 58.7 million hectares or 145 million acres, grown by approximately 6.0 million farmers in 16 countries, up from 13 countries in 2001. The increase in area between 2001 and 2002 was 12%, equivalent to 6.1 million hectares or 15 million acres, and 2002 was the first year when more developing countries (9) grew GM crops than industrial countries (7), Table 63.1. More than one quarter (27%) of the global transgenic crop area of 58.7 million hectares in 2002, equivalent to 16.0 million hectares, was grown in developing countries where growth continued to be strong. Whereas the absolute growth in GM crop area between 2001 and 2002 was higher in industrial countries (3.6 million hectares) compared with developing countries (2.5 million hectares), the percentage growth was more than twice as high in the developing countries of the south (19%) than in the industrial countries of the north (9%).

In 2002, four principal countries grew 99% of the global transgenic crop area (Table 63.1). The United States grew 39.0 million hectares (66% of the global total), followed by Argentina with 13.5 million hectares (23%), Canada 3.5 million hectares (6%) and China 2.1 million hectares (4%). Of the four leading GM crop countries, China had the highest year-on-year growth with a 40% increase in its Bt cotton area from 1.5 million hectares in 2001 to 2.1 million hectares in 2002, equivalent to 51% of the total cotton area of 4.1 million hectares; this is the first time for the Bt cotton area in China to exceed more than half of the national cotton area. Despite the economic crisis in Argentina, its GM crop area grew at 14% from 11.8 million hectares in 2001 to 13.5 million hectares in 2002. A growth rate of 9% was achieved in both the United States (equivalent to 3.3 million hectares) and Canada (0.3 million hectares). GM crop hectarage increased in South Africa by over 20% to 0.3 million hectares. Three developing countries, India, Colombia and Honduras grew transgenic crops for the first time in 2002. Notably, India, the largest cotton growing country in the world, with 8.7 million hectares equivalent to 25% of the world cotton hectarage, planted 45 000 hectares of commercial Bt cotton for the first time in 2002. Colombia also planted an introductory pre-commercial area of up to 2000 hectares of Bt cotton for the first time in 2002. Honduras became the first country in Central America to grow an introductory pre-commercial area of approximately 350 hectares of Bt corn in 2002. Thus, the number of countries that grew GM crops increased from 13 in 2001 to 16 in 2002—these include nine developing countries, five industrial countries and two Eastern European countries.

Globally, in 2002, the principal GM crops were: GM soybean occupying 36.5 million hectares (62% of global area), up from 33.3 million hectares in 2001; GM corn at 12.4 million hectares (21%), up from 9.8 million hectares in 2001; transgenic cotton at the same level of 6.8 million hectares (12%); and GM canola at 3.0 million hectares (5%), up from 2.7 million hectares in 2001, (James, 2002a). During the seven-year period 1996–2002, herbicide tolerance has consistently been the dominant trait with insect resistance being second. In 2002, herbicide tolerance, deployed in soybean, corn and cotton, occupied 75% or 44.2 million hectares of the global GM 58.7 million hectares, with 10.1 million hectares (17%) planted to Bt crops. Stacked genes for both herbicide tolerance and insect resistance deployed in both cotton and corn occupied 8% or 4.4 million hectares of the global transgenic area in 2002. The two dominant GM crop trait combinations in 2002 were: herbicide-tolerant soybean occupying 36.5 million hectares or 62% of the global total and grown in seven countries, and Bt maize, occupying 7.7 million hectares, equivalent to 13% of global transgenic area and also planted in seven countries. Notably, South Africa grew 58 000 hectares of Bt white maize for food, up 10-fold from 2001; herbicide-tolerant canola was planted in Canada and the United States occuping 3.0 million hectares equivalent to 5% of global transgenic area; the other five GM crops, herbicide-tolerant maize and cotton, Bt cotton and Bt/herbicide-tolerant cotton and maize, each occupied 4% of global transgenic crop area.

Another useful way to portray the adoption of GM crops is to express the global adoption rates for the four principal GM crops in 2001, soybean, cotton, canola and corn (James, 2002b). The data indicate that for the first time the GM soybean area exceeded 50% of the global hectarage of soybean. In 2002, 51% of the 72 million hectares of soybean planted globally were transgenic—up from 46% in 2001. Twenty per cent of the 34 million hectares of cotton were GM, the same as last year; decreases in total plantings of cotton in the United States (down by approximately 10%) and Australia (down by approximately. 50% due to a severe drought) were offset by a significant increase in GM cotton in China and the first planting of Bt cotton in India. The areas planted to transgenic canola and maize, both increased in 2002. Of the global 25 million hectares of canola, the percentage of GM increased from 11% in 2001 to 12% in 2002. Similarly, of the 140 million hectares of maize grown globally, 9% were GM in 2002—up significantly from 7% in 2001. If the global areas (conventional and transgenic) of these four principal GM crops are aggregated, the total area is 271 million hectares of which 21%, up from 19% in 2001, was transgenic in 2002. The biggest increase in 2002 is a 3.2 million hectares increase in GM soybean equivalent to a 10% year-on-year increase, followed by a 2.6 million hectares increase in GM maize equivalent to a significant 27% year-on-year growth.

The global population reached six billion on 12 October 1999, and is expected to reach nine billion by 2050, when approximately 90% of the world's population will live, or survive, in the three continents of the South: Asia, Africa and Latin America where today malnutrition results in 24 000 deaths per day. Thus, in the next 50 years, the population will increase by 50%, or three billion, and food production will need to be doubled on the same area of arable land (1.5 billion hectares), by 2050. The magnitude of the challenge of feeding tomorrow's world is difficult to conceive and the enormity of the task is probably best captured by the statement that: ‘In the next fifty years mankind will consume twice as much food as mankind has consumed since the beginning of agriculture, 10 000 years ago’ (James, 2002a, 2002b).

Crops are the major source of food globally. There is a widely held view in the international scientific and development community that conventional crop improvement alone will not allow us to meet the global food demands of 2050. What is being advocated is a global strategy that integrates both conventional crop improvement and biotechnology, including transgenic crops, which are often referred to as genetically modified (GM) crops; adoption of such a strategy would allow society to harness and optimise the contribution of biotechnology and GM crops to global food security. There is cautious optimism that such a strategy would contribute significantly to the alleviation of poverty and malnutrition which afflict 1.3 billion people and 815 million people, respectively, today, and that the global food demands of 2050 and beyond can be met.

China was the first country to commercialise transgenic crops in the early 1990s. The first approval for commercial sale of a genetically modified product for food use in an industrialised country was in the United States in 1994, but significant commercialisation did not actually begin until 1996. The unprecedented rapid adoption of transgenic crops during the initial seven-year period, 1996–2002 (Figure 63.1), when GM crops were first adopted, reflects the significant multiple benefits realised by large and small farmers in the industrial and developing countries that have grown transgenic crops commercially. Between 1996 and 2002, a total of 19 countries, 10 industrial and 9 developing, contributed to a more than 35-fold increase in the global area of transgenic crops from 1.7 million hectares in 1996 to 58.7 million hectares in 2002 (James, 2002a). The accumulated area of transgenic crops planted globally in the seven-year period, 1996–2002, totals more than 235 million hectares, equivalent to more than 575 million acres, an area equivalent to 25% of the land area of China or the United States, and 10 times greater than the land area of the UK.

In 2002, the global area of transgenic crops continued to grow for the sixth consecutive year at a sustained rate of growth of more than 10% between 2001 and 2002. The estimated global area of transgenic or GM crops for 2002 was 58.7 million hectares or 145 million acres, grown by approximately 6.0 million farmers in 16 countries, up from 13 countries in 2001. The increase in area between 2001 and 2002 was 12%, equivalent to 6.1 million hectares or 15 million acres, and 2002 was the first year when more developing countries (9) grew GM crops than industrial countries (7), Table 63.1. More than one quarter (27%) of the global transgenic crop area of 58.7 million hectares in 2002, equivalent to 16.0 million hectares, was grown in developing countries where growth continued to be strong. Whereas the absolute growth in GM crop area between 2001 and 2002 was higher in industrial countries (3.6 million hectares) compared with developing countries (2.5 million hectares), the percentage growth was more than twice as high in the developing countries of the south (19%) than in the industrial countries of the north (9%).

In 2002, four principal countries grew 99% of the global transgenic crop area (Table 63.1). The United States grew 39.0 million hectares (66% of the global total), followed by Argentina with 13.5 million hectares (23%), Canada 3.5 million hectares (6%) and China 2.1 million hectares (4%). Of the four leading GM crop countries, China had the highest year-on-year growth with a 40% increase in its Bt cotton area from 1.5 million hectares in 2001 to 2.1 million hectares in 2002, equivalent to 51% of the total cotton area of 4.1 million hectares; this is the first time for the Bt cotton area in China to exceed more than half of the national cotton area. Despite the economic crisis in Argentina, its GM crop area grew at 14% from 11.8 million hectares in 2001 to 13.5 million hectares in 2002. A growth rate of 9% was achieved in both the United States (equivalent to 3.3 million hectares) and Canada (0.3 million hectares). GM crop hectarage increased in South Africa by over 20% to 0.3 million hectares. Three developing countries, India, Colombia and Honduras grew transgenic crops for the first time in 2002. Notably, India, the largest cotton growing country in the world, with 8.7 million hectares equivalent to 25% of the world cotton hectarage, planted 45 000 hectares of commercial Bt cotton for the first time in 2002. Colombia also planted an introductory pre-commercial area of up to 2000 hectares of Bt cotton for the first time in 2002. Honduras became the first country in Central America to grow an introductory pre-commercial area of approximately 350 hectares of Bt corn in 2002. Thus, the number of countries that grew GM crops increased from 13 in 2001 to 16 in 2002—these include nine developing countries, five industrial countries and two Eastern European countries.

Globally, in 2002, the principal GM crops were: GM soybean occupying 36.5 million hectares (62% of global area), up from 33.3 million hectares in 2001; GM corn at 12.4 million hectares (21%), up from 9.8 million hectares in 2001; transgenic cotton at the same level of 6.8 million hectares (12%); and GM canola at 3.0 million hectares (5%), up from 2.7 million hectares in 2001, (James, 2002a). During the seven-year period 1996–2002, herbicide tolerance has consistently been the dominant trait with insect resistance being second. In 2002, herbicide tolerance, deployed in soybean, corn and cotton, occupied 75% or 44.2 million hectares of the global GM 58.7 million hectares, with 10.1 million hectares (17%) planted to Bt crops. Stacked genes for both herbicide tolerance and insect resistance deployed in both cotton and corn occupied 8% or 4.4 million hectares of the global transgenic area in 2002. The two dominant GM crop trait combinations in 2002 were: herbicide-tolerant soybean occupying 36.5 million hectares or 62% of the global total and grown in seven countries, and Bt maize, occupying 7.7 million hectares, equivalent to 13% of global transgenic area and also planted in seven countries. Notably, South Africa grew 58 000 hectares of Bt white maize for food, up 10-fold from 2001; herbicide-tolerant canola was planted in Canada and the United States occuping 3.0 million hectares equivalent to 5% of global transgenic area; the other five GM crops, herbicide-tolerant maize and cotton, Bt cotton and Bt/herbicide-tolerant cotton and maize, each occupied 4% of global transgenic crop area.

Another useful way to portray the adoption of GM crops is to express the global adoption rates for the four principal GM crops in 2001, soybean, cotton, canola and corn (James, 2002b). The data indicate that for the first time the GM soybean area exceeded 50% of the global hectarage of soybean. In 2002, 51% of the 72 million hectares of soybean planted globally were transgenic—up from 46% in 2001. Twenty per cent of the 34 million hectares of cotton were GM, the same as last year; decreases in total plantings of cotton in the United States (down by approximately 10%) and Australia (down by approximately. 50% due to a severe drought) were offset by a significant increase in GM cotton in China and the first planting of Bt cotton in India. The areas planted to transgenic canola and maize, both increased in 2002. Of the global 25 million hectares of canola, the percentage of GM increased from 11% in 2001 to 12% in 2002. Similarly, of the 140 million hectares of maize grown globally, 9% were GM in 2002—up significantly from 7% in 2001. If the global areas (conventional and transgenic) of these four principal GM crops are aggregated, the total area is 271 million hectares of which 21%, up from 19% in 2001, was transgenic in 2002. The biggest increase in 2002 is a 3.2 million hectares increase in GM soybean equivalent to a 10% year-on-year increase, followed by a 2.6 million hectares increase in GM maize equivalent to a significant 27% year-on-year growth.

How to Produce Haploid Plant ?

Haploids are defined as saprophytes with gametophytic chromosome number and have been produced in a variety of plant species using a variety of methods.

Although, the significance of haploids in genetics and plant breeding has been recognized for long time, with the advent of new biotechnology it has received renewed emphasis, so that the production of haploids has become an important component of biotechnology programmes in different countries.
Although, haploids could be produced following delayed pollination, irradiation of pollen, temperature shocks, colchicine treatment and distant hybridization, the most important methods currently being utilized under biotechnology programmes include

(i) anther or pollen culture and ovule culture and
(ii) chromosome elimination following interspecific hybridization (bulbosum technique).
Factors Affecting Haploid Production

- A number of factors influence androgenesis in vitro. The genotype of the donor plant plays a significant role in determining the frequency of pollen plant production. Anther wall factors also support pollen embryo development.

Histological studies support this view. As induction of the pollen into embryoids occurs most easily within the confines of an anther, the anther wall seems to provide a nursing effect. There are two schools of thought regarding the role of the anther wall. One is that it may have a stimulatory effect on the growth of pollen embryos (probably due to the presence of enhanced levels of some amino acids such as glutamine and serine); the other view holds that it may emanate some inhibitory substances into the culture medium thereby blocking the growth of more pollen into embryos.
The culture medium also plays a vital role since the requirements vary with the genotype and probably the age of the anther as well as conditions under which donor plants are grown. The medium should contain the correct amount and proportion of inorganic nutrients to satisfy the nutritional as well as physiological needs of the many plant cells in culture.

In addition to basal salts and vitamins, hormones in the medium are critical factors for embryo or callus formation. Cytokinins (e.g. kinetin) are necessary for induction of pollen embryos in many species of Solanaceae except tobacco. Auxins, in particular 2,4-0, greatly promote the formation of pollen callus in cereals. For regeneration of plants from pollen calli, a cytokinin and lower concentration of auxin are often necessary.

Sucrose has been considered the most effective carbohydrate source which cannot be substituted by other disaccharides. Glucose can be used in anther culture in some cases but fructose is far less effective. The concentration of sucrose also plays an important role in induction of pollen plants. Activated charcoal is also added to the culture medium.
It helps in the removal of inhibitors from the agar used for gelling the medium. Another role assigned to activated charcoal is the adsorption of 5¬hydroxymethylfurfural, a product of sucrose dehydration during autoclaving, assumed to bean inhibitor of growth in anther cultures.

Certain organic supplements added to the culture medium often enhance the growth of anther cultures. Some of these include the hydrolyzed products of proteins such as casein (found in milk), nucleic acids, and others. Coconut milk obtained from tender coconuts is often added to tissue culture media. It contains a complex mixture of nucleic acids, sugars, growth hormones and some vitamins.

The physiological state of the parent plant plays a role in haploid production. Success in haploid induction is in part dependent on knowledge of the physiology of the pollen yielding plant. In various plant species it has been shown that the frequency of androgenesis is higher in anthers harvested at the beginning of the flowering period and declines with plant age.
This may be due to deterioration in the general condition of the plants, especially during seed set. The lower frequency of induction of haploids in anthers taken from older plants may also be associated with a decline in pollen viability. Seasonal variations, physical treatment, and application of hormones and salts to the plant also alter its physiological status, which is reflected in a change in anther response.

Temperature and light are two physical factors which play an important role in culture of anthers. Higher temperatures (30°C) yield better results. Temperature shocks also enhance the induction frequency of microspore androgenesis. Frequency of haploid formation and growth of plantlets are generally better in light.
Certain physical and chemical treatments given to flower, buds or anthers prior to culture, can be highly conducive to the development of pollen into plants. The most significant is cold treatment.
The developmental stage of pollen greatly influences the fate of the microspore, Androgenesis occurs when a microspore or pollen is induced to shift from a gametophytic pathway to a sporophytic pathway of embryo formation.

Anthers of some species (Datura, tobacco) give the best response if pollen is cultured at first. mitosis or later stages (postmitotic), whereas in most others (barley, wheat, rice) anthers are most productive when cultured at the uninucleate microspore stage (premitotic). Anthers at a very young stage (containing microspore mother cells m tetrads) or a late stage (containing binucleate, starch filled pollen) of development are generally ineffective, albeit some exceptions are known.

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Types of Seed Dormancy

This review will focus on the process of primary seed dormancy. As noted above, primary dormancy is characterised by a transient inability of mature dispersed seeds to germinate under conditions that are normally conducive to germination (Grappin et al., 2000); the inception of primary dormancy occurs during seed development (reviewed in Bewley, 1997) . Dormancy can also be induced in mature, already dispersed, nondormant seeds (known as induced or secondary dormancy) by environmental conditions that are unfavourable for germination, e.g. anoxia, unsuitable temperatures or illumination (Bewley, 1997). In induced dormancy, the seed loses its sensitivity to dormancy-breaking factors (e.g. light, nitrate, etc., depending on the species) (Bewley and Black, 1994).

Primary dormancy is generally classed into two major types: embryo dormancy and coat-imposed dormancy (more accurately termed coat-enhanced dormancy) (Bewley and Black, 1994). In embryo dormancy, it is the embryo that is dormant and the embryonic axis will not elongate even if the embryo is excised from its enclosing seed tissues and placed on water. In coat-enhanced dormancy, the embryo, when isolated is capable of germination, but the intact seed is dormant; thus, it is the surrounding seed tissues that impose the block to germination. The inhibitory nature of the enclosing seed tissues may be attributed to one or a combination of the following effects: (1) interference with water uptake; (2) mechanical restraint; (3) interference with gas exchange; (4) supply of inhibitors to the embryo or promotion of the synthesis of inhibitors within the embryo and (5) prevention of the exit of inhibitors from the embryo (Bewley and Black, 1994). For many seeds, more than one of these factors operates to maintain coat-enhanced dormancy.

A variety of germination inhibitors have been identified within the seed tissues that enclose the embryo. While their presence does not necessarily imply a causal role in preventing germination, in many cases, where repeated washing (leaching) of seeds relieves dormancy, inhibitors are known to be removed (Bewley and Black, 1994). The inhibitor that has received the most attention with respect to dormancy imposition and maintenance is ABA .

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Seeds control the survival and reproductive capacity of plants

Seeds control the survival and reproductive capacity of plants and therefore occupy a critical position in the life history of higher plants. The successful establishment of the new plant, both temporally and spatially, as well as the vigour of the young seedling, is largely determined by physiological and biochemical processes that occurred earlier, i.e. during seed development. At dispersal, the quiescent mature seed, upon encountering favourable environmental conditions (that can include light of a given wavelength, sufficient water, optimal temperatures and adequate oxygen), commences germination.

Germination, sensu stricto includes those events commencing with imbibition or uptake of water by the quiescent dry seed and culminates with the elongation of the radicle (Bewley and Black, 1994; Bewley, 1997). It is accompanied by a reactivation of metabolic systems, a process that depends in part on components that were preserved during seed desiccation as well as on components that are de novo synthesised. Ultimately, there is renewed cell expansion (elongation of the radicle) and cell division as the seedling becomes established (Figure 33.1). Visible evidence of the completion of germination is usually protrusion of the radicle through the seed structures surrounding the embryo (such as the testa and endosperm, or megagametophyte).

Subsequent events, including activation of the shoot apical meristem and the mobilization of the major storage reserves are associated with the growth of the seedling. Some seeds fail to complete germination under seemingly favourable conditions, even though they are viable. These dormant seeds must be exposed to environmental cues such as periods of warm-dry conditions (after-ripening), moist chilling, or even smoke for dormancy to be terminated (Adkins et al., 1986; Egerton-Warburton, 1998).

Although generally considered an undesirable trait by the agricultural and forest industries, dormancy in nature is clearly an adaptive trait, since it improves survival by optimising the distribution of germination over time. For example, a seed that germinates in spring after remaining dormant throughout the winter has a greater chance of successful seedling establishment than that which germinates immediately after its dispersal in the fall. Seed dormancy can also lead to a distribution of germination in space (Bewley and Black, 1994). Consider those seeds whose dormancy is terminated by light, the most effective wavelengths being 660 nm (the red region of the spectrum).

This mechanism prevents these seeds from germinating and attempting seedling establishment under competitive situations (e.g. in light transmitted through green leaves, since it is poor in the red component) or when the seeds are buried at depths in the soil to which suitable light cannot penetrate. These seeds readily germinate when close to the soil surface and when unrestricted by leaf canopies. Since seedling emergence from the soil is supported solely by mobilisation of the seed's reserves, some of these mechanisms for preventing germination occur in small seeds that contain a limited amount of stored reserves (Bewley and Black, 1994).

Once a seed has initiated cell division and becomes a seedling, it passes from its most stress-resistant state to its most stress-susceptible state, during which it is highly vulnerable to environmental conditions, and there is no reversal to a resistant state. However, as will be discussed, under conditions that are not optimal for a transition from germination to seedling growth, seeds express genes that impose a transient ‘quiescence’ until those conditions become optimal. Thus, control of seed germination and growth is crucial to the survival of seeds and there are critical checkpoints at the transitions from dormancy to germination and from germination to growth.

The agricultural and forest industries rely upon seeds that exhibit high germinability and vigorous, synchronous growth after germination; hence dormancy is generally considered an undesirable trait. In agriculture, extensive breeding programmes have reduced the degree of dormancy as well as improving other traits of crops, particularly yield. In the forest industry, tree orchards have been established in order to meet the planting demands for several conifer species. Here breeding programmes are complicated by the fact that the generation time for trees are untimely long and many species are characterised by a deeply manifested dormancy. Moreover, maintaining genetic diversity is a key endeavour. Some of the problems unique to the forest industry in relation to the deep dormancy of conifer species will be discussed.

Functional genomics approaches hold promise for elucidating genes and proteins that control seed dormancy and germination. The understanding of molecular and physiological mechanisms underlying seed dormancy, particularly of angiosperms, has been accelerated through the analysis of mutants that are disrupted in their development (including dormancy inception and maintenance) as a result of a deficiency in hormone biosynthesis or response. Cloning of the genes that are defective in these mutants has opened up avenues to reduce dormancy by altering specific traits (genes) through the technology of gene transfer. The recent cloning of the genes encoding key enzymes for the metabolism of abscisic acid (ABA) (i.e. ABA 8′-hydroxylase and ABA glucosyltransferase) may also lead to unique approaches for germination control. These and other biotechnological approaches for manipulating germination will be discussed.

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