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Results of Transgenic Wheat Trial Look Promising

September, 2004

CIMMYT took a historic step in March 2004 by planting a small trial of genetically engineered wheat in its screenhouse at headquarters in El Batan, Mexico. It was the first time that transgenic wheat has been planted in Mexico under field-like conditions, and encouraging results have spurred plans for a more extensive follow-up trial.

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dreb_02 DREB plants (left) next to non-DREB plants (right) in the trial.
Striving for Drought-Tolerant Wheat

Researchers used genetic engineering to insert a gene from Arabidopsis thaliana, a relative of wild mustard, into wheat. The gene, DREB1A, was provided by the Japan International Research Center for Agricultural Sciences, and has been shown to confer tolerance to drought, low temperature, and salinity in its natural host. The small trial completed this year was conducted in full accordance with Mexican and CIMMYT biosafety procedures, and represents a critical step toward developing drought-tolerant wheat varieties by allowing scientists to see how the DREB1A-expressing wheat responds under more natural conditions.

Drought is one of the most important agricultural production problems in the world. Combined with shortages of irrigation water, it threatens the ability of many developing countries to produce enough grain to feed themselves. Currently, the 20% of global farmland that produces 40% of the world’s food supply is irrigated.

“Drought is a complicated problem,” says CIMMYT cell biologist Alessandro Pellegrineschi, who led the trial. “When a plant is exposed to drought, there can be moisture stress, but there can also be heat or soil micro-element deficiencies or toxicities.” Because there are so many stresses, it is important to evaluate a potential solution under a variety of environments. Moreover, scientists are discovering that plants react to numerous stresses, especially to water deficiency and high levels of salt, in complex ways.

Encouraging and Consistent Results

Looking at the trial results, Pellegrineschi and colleagues were encouraged when they observed a more normal, non-stressed phenotype in the transgenic lines under drought conditions. Near the trial’s end, the non-DREB control wheat was dry, yellow, and shriveled, while the DREB wheat was still green and thriving. Pellegrineschi was surprised that a single gene could bring about such a visible response.

Pellegrineschi says the results of this trial, which is part of CIMMYT’s joint work with the Australian Cooperative Research Centre for Molecular Plant Breeding, are compatible with previous observations from small pots in the biosafety greenhouse. Many of the measured traits correlated with the improved performance of transgenic lines under water stress. However, the results need to be verified in a larger field trial with selected transgenic lines.

Taking Precautions

This is the first time that a food crop carrying the DREB1A gene has advanced to this level of testing. The Mexican government, which had announced a moratorium on planting transgenic maize under field conditions in 1998, approved the trial in December 2003.

CIMMYT followed strict biosafety procedures and worked closely with the government of Mexico in planning, conducting, and monitoring the trial. Access to the screenhouse was restricted. The researchers covered all plant flowers with bags and did not allow other wheat plants to grow within 10 meters of the trial, even though it is unlikely that self-pollinating wheat plants would cross with each other. After the trial, all plant materials except the harvested seed were destroyed.

What Next?

“This was the first trial transgenic wheat trial after the government removed the moratorium on growing transgenic varieties under field conditions, so we were very conservative in our request to the Mexican authorities for approval of the initial trial,” says Pellegrineschi. “Now that we have had some success, we will submit a request for a larger trial.”

Pending approval from the Mexican authorities, researchers are ready to begin a second trial, which will evaluate the best performing lines from the first trial more closely. In response to lessons learned from the first trial, the researchers are going to use a larger plot, have more replications, and restrict walking and the resultant soil compaction in the plots.

Five years ago, many people thought it was unrealistic that a single gene could improve a complex trait such as drought tolerance. With the right approaches, including the investment in proper field trials, Pellegrineschi believes that it will be possible to produce lines containing effective transgenes within five years.

Why Genetic Engineering?

With genetic engineering, useful genes for traits of interest can be transferred across species. DNA can be directly inserted into individual plant cells. The genetically altered tissue can be regenerated into complete plants and later transferred through conventional breeding into entire lines and varieties. This approach may also applied to rapidly and efficiently transfer traits within species for either research or development purposes. In both instances, CIMMYT remains committed to generating end-products that carry only the gene(s) of interest–that is, the undesired genes (marker genes) have been removed through conventional breeding.

Genetic engineering could increase the productivity and profitability of farming through reduced input use (lowering costs), added pest or disease resistance, and crops with better nutritional content or storage characteristics. Also, genetic engineering may solve problems that conventional breeding methods cannot. Nutritionally fortified crop varieties could be especially valuable in developing countries where millions of people suffer from dietary deficiencies.

Genetic engineering could become an important tool for introducing beneficial traits into maize and wheat. Efforts such as the DREB wheat field trail will allow our scientists to use a range of genes for the benefit of farmers and to pass on the products of cutting-edge technology to research partners in developing countries.

For more information: Alessandro Pellegrineschi or David Hoisington

Nepal-CIMMYT partnerships reach the unreached

nov1More than two decades of joint efforts between researchers from Nepal and CIMMYT have helped boost the country’s maize yields 36% and those of wheat by 85%, according to a report compiled to mark the 25th anniversary of the partnership. As a result, farmers even in the country’s remote, mid hill mountain areas have more food and brighter futures.

Anywhere else, peaks above 3,000 meters would be called “mountains,” but a nation whose collective psyche has been shaped by the towering Himalayas refers to its rugged heartland as merely the “mid-hills.” Comprising deep river valleys and high ridge tops, peppered toward the north with sloping farm terraces, the mid-hills account for more than four-tenths of Nepal’s total land area. They are home to isolated villages whose inhabitants’ lives hold strongly to tradition.

One such villager is Bishnu Maya Nepali, 45 from, Belhara village of Dhankuta district. She is a farmer and a single mother of three. Maya is a “dalit,” one of the poorest castes in the Nepal’s traditional caste hierarchical system.

Up until a few years ago, Maya maintained a hardscrabble existence by planting maize, the region’s main food crop. Like many area farmers, it wasn’t enough. Her farm–which is roughly the size of a soccer field–didn’t produce enough food to feed her family.

Maya’s life began to change in 2006 when she was approached by members of the HMRP. Maya was asked to test maize varieties bred for the mid-hills by the Nepal Agriculture Research Council (NARC) with CIMMYT as one of the partners. She agreed and eventually decided to plant a type of maize, called Manakamana 3, which produced two large ears per plant and which had a shorter, sturdier stalk. To her delight, the new plant thrived. Maya’s maize harvests grew 20-50%. She also discovered the plant stayed green as it matured, providing better forage for her livestock. The project advised Maya to plant vegetables in addition to maize. These intercrops also did well, bringing Maya additional food and income. Maya grew enough food to feed her three children all year long. “Now I have enough food and can sell some surplus to pay for my children’s education,” she said. Maya’s additional income allowed her to put her children into school and even make modest improvements to her homestead.

Support for an agrarian way of life
Nepal is a nation of incredible diversity that depends heavily on agriculture. Of the Nepalese population, 84% live in rural areas and, during the growing season, four of every five adults of the rural population are engaged in agriculture.

In September 2010, Nepal and CIMMYT celebrated 25 years of partnership in developing and spreading improved maize and wheat varieties and cropping practices in benefit of Nepalese farmers and researchers. Given the country’s reliance on agriculture and its financial constraints, the partnership has been invaluable. “Maya’s case is just one example of this,” says Guillermo OrtĂ­z-Ferrara, researcher and liaison officer for CIMMYT’s office in Nepal. The joint efforts have helped raise maize yields 36% and those of wheat by 85%, while 170 Nepali researchers have benefited from CIMMYT training and joint research or fellowships. “The partnership that CIMMYT has maintained over the past 25 years with our research and development institutions in Nepal has been very useful and of significant value to increase maize and wheat production,” says Dr. K.K. Lal, one of the very first CIMMYT maize trainees and former Joint Secretary in the Ministry of Agriculture and Cooperatives of Nepal. “This partnership should continue and be strengthened.”

Fig. 1 Major shift in food security in HMRP collaborating households
Fig. 1 Major shift in food security in HMRP collaborating households

An internal report on HMRP outcomes for 2008-10 by the Swiss Agency for Development and Cooperation showed significant improvements in food security for the more than 21,000 households taking part in the project, with particular focus on women and disadvantaged groups like dalits: the proportion of the population in the groups having food sufficiency throughout most or all of the year (first two sets of bars) grew, while the proportion of the food-insecure—those with enough food for less than six months of the year (last set of bars)—fell.

The Hill Maize Research Program
Begun in 1999 with the cooperation of the National Maize Research Program (NMRP) of the Nepal Agriculture Research Council (NARC), the Hill Maize Research Program (HMRP) promotes the development and adoption of new technologies (improved varieties and crop management) in the hills of Nepal. Funded by the Swiss Agency for Development and Cooperation (SDC), the HMRP works with government, non-government organizations, farmers groups and cooperatives and the private sector to develop and disseminate maize technologies that benefit poor farmers in the Nepali hills. With HMRP-CIMMYT support, NMRP has developed 12 improved maize varieties for commercial production and identified more than 15 promising inbred lines, including 4 QPM lines. These 12 improved maize varieties were released by National Seed Board (NSB) of Government of Nepal. By 2009, 174 farmers groups had produced 664 tons of improved maize seed, increasing maize productivity by at least 30%. A new 2010-14 phase of the HMRP continues the focus on improving the food security and incomes of Nepal hill farm families, especially the poor and disadvantaged. Partners include the Ministry of Agriculture and Cooperatives (MoAC), the Nepal Agricultural Research Council (NARC), the Department of Agriculture (DoA), more than 26 NGOs/CBOs, and thousands of poor farmers. The new phase is jointly funded by SDC and the United States Agency for International Development (USAID).

Winning with wheat
Along with maize, the importance of wheat as a food and cash crop has grown in Nepal. As a result of high-yielding Mexican varieties introduced through CIMMYT during the mid-1960s and intensive research and development efforts by the national partners, Nepal’s wheat area has increased 7-fold, its production 14-fold, and its productivity 2-fold. Overall, yield gains from the release of new varieties in Nepal have averaged 3.5% per year since 1985, which equals or exceeds the yield gains seen in neighboring countries where the Green Revolution began.

nov07During 1997-2008, Nepal’s National Wheat Research Program (NWRP) worked in partnership with CIMMYT, involving farmers in varietal selection and distributing regional nurseries—sets of experimental wheat lines sent out for widespread testing and possible use in breeding programs. Two wheat varieties distributed this way, and bred by the NWRP, have been released in Bangladesh, and a significant number of other Nepali breeding lines have been used in research programs of Nepal and in eastern India.

Farming systems for a tough future
The Nepal-CIMMYT partnership has addressed important farming concerns with research and recommendations on varieties for timely and late sown conditions, appropriate weed management, balanced application of fertilizers, irrigation schedules, and resource-conserving practices such as surface seeding, zero and minimum tillage, and bed planting. The best results have included reduced costs for cropping, greater efficiency of input use, and increases of a ton or more per hectare in grain yields.

“South Asia will suffer particularly harsh effects from climate change, according to experts,” says Mr. Kamal Aryal, Agriculture/Climate Change Researcher, ICIMOD, Kathmandu, Nepal. “More input-efficient cropping systems will help farmers face the challenges expected.”

For more information: Guillermo Ortiz-Ferrara, cereal breeder (g.ortiz-ferrara@cgiar.org)

Moving uphill: Maize’s growing role in Ethiopia

CIMMYT E-News, vol 6 no. 1, January 2009

 

Fueled by high-yielding varieties and national initiatives to promote the crop in highland areas, maize’s popularity is mounting rapidly in Ethiopia. Because farmers can get more food and income with the new varieties, they are calling out for seed. Suppliers—both private and government supported—are clamoring to meet the demand

“Farmers have expressed strong feelings for maize,” says a translator. A group of villagers at Sororo, Ejere District, Oromia, stand in the intense, mid-morning glare of highland Ethiopia and speak to visitors about their experiences with the improved maize varieties they had received from Demissew Abakemal, maize breeder with the Ethiopian Institute of Agricultural Research (EIAR). “It was a very dry year, and your maize is performing well,” the farmers say. “We have a surplus for food and even some for taking to the market—something we’d not seen in all our lives.” They have been harvesting and piling sheaves of wheat from the bottom of the hill, but take the visitors to maize fields up near their dwellings, and proudly show the large ears of the hybrid Arganne and a nearly-as-productive open-pollinated variety (OPV), Hora.

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CIMMYT brings the best in wheat

CIMMYT E-News, vol 3 no. 3, March 2006

mar_symptraver2Scientists talk wheat at the place where the green revolution began

Prominent players in global wheat research—hailing from Azerbaijan to Zimbabwe and about 20 countries in between—arrived at Ciudad Obregón, Mexico in late March to chart a course for wheat research in the developing world for the coming decade.

Approximately 130 participants attended the weeklong “International Symposium on Wheat Yield Potential: Challenges to International Wheat Breeding,” sponsored by CIMMYT and the Australian Centre for International Agricultural Research (ACIAR).

“This symposium has been a tremendous opportunity for sharing ideas and learning right across the world’s wheat research fraternity,” concludes Tony Fischer, ACIAR Program Advisor for South Asia. “The representation from both the developing and the developed world is very good and we once again see that in the developing world innovation system CIMMYT continues to play a huge leadership role.”

“The original purpose,” says symposium organizer and CIMMYT wheat physiologist Matthew Reynolds, “was to disseminate new technologies that would improve the efficiency of wheat breeding in lesser developed countries. We achieved that and much more. We delivered the results of our ACIAR project on early generation selection and improved understanding of the fundamental constraints to yield potential, but then went on to a wide range of very topical subjects covered by top experts in the field.”

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The meeting opened with a keynote address by Dr. Norman Borlaug entitled “Personal Reflections of 62 Years of Fighting Hunger.” Following the warmly received address, the symposium got down to business with a series of 40 technical presentations. A poster session addressing wheat breeding and production (and related constraints) in 17 countries ensured that NARS perspectives were well represented. The concluding day of the meeting was devoted to breakout and reporting sessions to define wheat research initiatives and explore the roles of CIMMYT, advanced research institutes, and NARS in putting the plans into action.

CIMMYT held a similar meeting nearly ten years ago to the day, which focused primarily on increasing yield potential, breeding for drought, and the use of molecular tools. While these items, particularly water use efficiency, remain high on CIMMYT’s agenda, the symposium participants observed that the world wheat situation and agriculture generally is rapidly changing, and consequently, new priorities have emerged. NARS representatives flagged high priority issues such as conservation agriculture, the need for higher quality wheat bred for specific food and industrial uses, and breeding with climate change in mind, notably heat stress.

Bayan Alimgazinova, Deputy Director, Science Department, Ministry of Agriculture of Kazakhstan

“CIMMYT provides and facilitates the exchange of germplasm and this is very important for our breeding efforts. The Kazakhstan-Siberia Network for Spring Wheat (KASIB) is a good example of this. It’s a new type of collaboration for us, with the shuttle breeding, traveling seminars, and other activities. We’ll be studying more than 1,000 entries in the trials and many of these will be useful for Kazakhstan. Our varieties go out as well. The impact of this is multiplied because all of the information from the trials and conferences gets published in journals (in Russian), as do a range of other publications and training course materials. CIMMYT is the main reason this is happening. A small but important component of our relationship with CIMMYT is the interaction with the outside scientific community that they provide to Kazak scientists.”

There were a number of exciting new ideas that emerged from this symposium, says Hans Braun, Director of the CIMMYT Wheat Program, “all of which depend on ever closer links between scientists in the international wheat community. In our final sessions we crystallized these into research thrusts that we would like to incorporate into our existing program.”

Braun said three major areas cited for more intensive research emerged from the interactions:

  • Integration of physiological trait-based approaches into conventional breeding schemes to advance progress on complex traits associated with yield and stress adaptation. This entails dissecting yield into its physiological components and using conceptual models to increase the likelihood of combining complementary genes to capture the desired trait. CIMMYT terms this use of physiological markers physiological breeding or “smart crossing.”
  • More systematic characterization of target environments than in the past. Combining comprehensive environment data with CIMMYT’s exceptional and extensive phenotypic data of genotypes will greatly expand our knowledge about genotype x environment interaction. This will be further catalyzed by new tools and methodologies in the areas of geographic information systems, advanced statistics, modeling, and bioinformatics.
  • Conservation agriculture (CA) was strongly endorsed as a strategy for buffering the adverse effects of environment on crop yields, especially in the face of climate change and reduced water resources. This is in addition to CA’s role in stabilizing the natural resource base and reducing long-term dependence on agro-chemical inputs.

For further information contact Matthew Reynolds (m.reynolds@cgiar.org)

New life for old varieties

CIMMYT E-News, vol 3 no. 11, November 2006

nov04A CIMMYT scientist is working to see if instead of replacing old varieties with “new and improved”, it is possible to combine the best of the new while retaining the old.

In the village of Tumbadero, Mexico, adjacent to CIMMYT’s Agua Fría maize research station, the farmers place a very high value on their traditional varieties. The maize they grow has small ears so it does not yield much. What makes each ear special is a long husk that dwarfs it. The village is close to a major transportation route and traders pay a premium for the husks, which are used to wrap one of Mexico’s most famous foods, the tamale. “We make more money selling the husks than we do selling the grain” says Ruben López, a farmer in the village. But he and the other villagers have a problem: storing the ears without their husks is an open invitation to insects to feast on the maize. With so little yield, saving every grain possible for food is extremely important.

Less than a hundred kilometers from Tumbadero is another village—Cañada Rica. It is well off the beaten track and far from traders. Farmers like Eva Cruz care much more about the cooking quality of the maize flour than they do about the husks, which they cannot sell. Eva uses husks as kindling for the fire on which she cooks tortillas each morning. “Our maize makes the best tortillas,” she says. “They are thick and filling, much better than ones you make with maize flour from the store.” But Eva Cruz’s maize is not without problems either. Storage pests attack her harvest regularly, just as they do the maize in Tumbadero.

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Clearly the traditional varieties grown by the farmers of these two villages are very different and have been bred by them to meet specific needs. Each variety is also well-adapted to its local environment. Farmers have no desire to abandon those traits, but also need maize that yields, stores, and tolerates stress better than their traditional varieties. That conundrum became a challenge for Dave Bergvinson, a CIMMYT entomologist who specializes in maize pests. “What if, instead of breeding whole new varieties on a mass scale, you gave the farmers themselves a chance to breed their own?” asks Bergvinson. “You take their best and combine it with our best and then let them do the rest.” To test the idea, he is working with farmers in isolated, economically disadvantaged regions in Mexico. He takes seed from farmers to a CIMMYT research site, like the station at Agua Fría, where he can cross it with CIMMYT maize that has the characteristics missing in the farmers’ varieties. Each cross is specific to a particular village or farmer. After one season of crossing, Bergvinson selects the progeny that perform the best and most closely match farmer preferences for husk, grain type, adaptation, and other traits. Finally, he returns seed of the improved local variety to the farmers. From then on each farmer has what is basically his traditional variety, but with certain improved characteristics.

According to Bergvinson, CIMMYT lacks the resources to carry out such work on a global scale. “It’s not a mass, large-scale solution,” says Bergvinson. “But it is a way of getting to the small pockets of deep poverty and giving those farmers a chance.” It also provides another way for breeders to get a true sense of what end-users of breeding products—the farmer and consumer—consider important.

The pilot project is only in it’s fourth season and there is much analysis to be done, but farmers like Eva Cruz and Ruben López have grown their new seed and can see the improvement. They also see that the traits they value so much in their maze have not been lost.

For more information, David Bergvinson (d.bergvinson@cgiar.org)

A Maize for Farmers on the Edge

May, 2005

peru01CIMMYT-Peru maize, Marginal 28, outstrips expectations for farmers in Peru

On a hillside that abuts more than 3,000 kilometers of Amazonian expanse beginning in Peru and reaching clear across Brazil to the Atlantic, farmer Virgilio Medina Bautista weeds his maize field under the stifling equatorial sun. He and his wife Sabina Bardales typically arise before dawn to cook a meal for their field workers, and will work all day until bedtime, around 9 p.m. “We come to the field with the food for brunch and ready to work,” Medina says. “It’s a hard life, but there’s no other way, for someone without an education.”

Like 90% of the farmers in this region of Peru—the lowland zones east of the Andes known as the “jungle”—as well as many on the coastal plains or in inter-Andean valleys, Medina sows Marginal 28. This open-pollinated maize variety, developed in the 1980s by Peru and CIMMYT, is popular for its high yields and broad adaptation. It provides two or three times the average yield of the local variety it replaced, and grows well in diverse environments. “Private companies have been trying to introduce maize hybrids here, but they yield only six tons per hectare,” says Edison Hidalgo, maize researcher from the National Institute of Agricultural Research (INIA) “El Porvenir” experiment station, whose staff help spread productive farming practices throughout the region. “Marginal 28 gives that or more, under similar management, and because it’s an open-pollinated variety, farmers don’t have to purchase new seed every season.”

Luis Narro, CIMMYT maize researcher in South America and a native of Peru who helped develop Marginal 28, says the cultivar’s adaptation and uses have far outstripped expectations. “This variety is sown most widely in jungle zones—truly marginal, lowland areas characterized by poor soils, heavy weeds, and frequent drought, to name a few constraints,” Narro says. “But I was just at a station in Ayacucho, at over 2,700 meters in the Andes, and saw seed production fields of Marginal 28 where the yields were probably going to hit seven tons per hectare.” Farmers in jungle areas use it chiefly in animal feeds or for export to the coast. Coastal farmers grow Marginal 28 because the seed is relatively cheap and yields high-quality forage for their dairy cattle. In the Andes, the grain goes for food and snacks.

Its adaptability may be explained in part by its genetically diverse pedigree, which even includes as a parent an internationally recognized variety from Thailand. “This suggests part of the value of a global organization like CIMMYT, which can combine contributions from around the world to develop a useful product for small-scale farmers,” Narro says.

Can Poor Farmers Stop Chopping Down Jungles?

peru02Despite the clear benefits of Marginal 28, Peruvian farmers are still struggling as markets shift, production costs rise, and maize prices remain low. Farmer Jorge Dávila Dávila, of Fundo San Carlos, in Picota Province, in the Amazon region of Peru, grows maize, cotton, banana, and beans on his 10-hectare homestead. Because he is relatively far from the trans-Andean highways leading to the coast, where maize is in heavy demand for use in poultry feed, middlemen pay him only US $70 per ton of maize grain—well below world market prices. “Maize is a losing proposition; that’s why so many farmers here are in debt,” he says. “They can’t take their maize to local companies for a better price, because they already owe it to the middlemen who provide inputs.”

Unlike most peers, Dávila makes ends meet through hard work and what he calls “an orderly approach” to farming. Many in the region slash and burn new brushland, cropping it for two or three seasons till fertility falls off, and then they move to new land. Dávila has stayed put for eight years on the same fields. “I tell my neighbors not to cut down their jungle,” he says. “I’ve seen that leaving it brings me rain.” With support from INIA researchers like Hidalgo, Dávila is testing conservation agriculture practices. For example, on one plot he plans to keep maize residues on the soil surface and seed the next crop directly into the soil without plowing. Research by CIMMYT and others has shown that this practice can cut production costs, trap and conserve moisture, and improve soil quality.

For further information, contact Luis Narro (l.narro@cgiar.org)

The Color Orange: Key to More Nutritious Maize?

CIMMYT E-News, vol 2 no. 10, October 2005

colorOrangeThe HarvestPlus Maize group examines progress toward breeding maize with enhanced pro-vitamins A, iron, and zinc.

CIMMYT maize scientists and colleagues from national programs in the key countries targeted by HarvestPlus reported significant progress in identifying maize with elevated concentrations of iron, zinc, and pro-vitamins A (chemicals the human body can convert to vitamin A) in their elite maize varieties and germplasm collections. The results of two years of work were presented at the second HarvestPlus Maize meeting hosted by EMBRAPA, the national agricultural research program of Brazil at their maize and sorghum research station in Sete Lagoas.

Maize is a key target crop for nutritional enhancement because it is so widely consumed in areas where high malnutrition—especially vitamin-A deficiency—exists. Scientists working in the HarvestPlus program hope eventually to breed high-quality, high-yielding maize with enhanced pro-vitamins A, iron, and zinc content. These micronutrients in maize will have to be in a form that survives processing and can be utilized by the human body.

The first planning meeting for the maize scientists was held in 2003 in Ethiopia. “We’ve come a long way since we first met two years ago,” says Kevin Pixley, the HarvestPlus Maize coordinator and Director of CIMMYT’s Tropical Ecosystems Program. “But we have also realized that this is a very complex subject with many assumptions that have to be validated.”

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CIMMYT maize breeder Dave Beck showed the group results of screening of CIMMYT elite highland and transition zone maize germplasm for enhanced levels of pro-vitamins A, zinc, and iron. HarvestPlus nutritionists have set minimum targets for the concentrations of these micronutrients in maize. The good news is that for zinc, CIMMYT has identified material that was already above the threshold. For iron the picture is less promising as existing lines identified have only 60 percent of the required minimum level for iron. For pro-vitamins A CIMMYT has examined hundreds of lines. The best CIMMYT lines have about 75 percent of the minimum requirement, but sources identified by project partners in the USA have the minimum required level of pro-vitamins A. The CIMMYT team is now breeding to enhance pro-vitamins A concentration for highland, transition zone, mid-altitude, and lowland-adapted materials.

A topic of keen interest at the meeting was how to convince people to adopt any nutritionally enhanced maize varieties that might be developed. In much of eastern and southern Africa, white maize is preferred over yellow maize. Scientists in Zambia and Zimbabwe had conducted studies about the acceptability of yellow maize. Both studies found that yellow maize is associated with food aid and that was one reason people did not want to eat it. Scientists know there is a strong correlation between the color of the maize and the total level of carotenoids. Some of these carotenoids are precursors for vitamin A “pro-vitamins A.” Torbert Rocheford, a professor of plant genetics at the University of Illinois, suggested that the debate should not actually be about yellow maize in many parts of Africa. He said what we should be talking about is orange maize—something new that will not carry the stigma of yellow maize but will have high pro-vitamins A content.

For further information, contact Kevin Pixley (k.pixley@cgiar.org).

South Asian Partners Host Trustees for Extended Field Visits

April, 2004
South Asian Partners Host Trustees for Extended Field Visits

Much of CIMMYT’s research focuses on improving the livelihoods and food security of poor households in South Asia, which is home to more of the world’s poor–43 percent–than any other region. To observe the impact of CIMMYT’s efforts there and to assess opportunities to help farmers, CIMMYT’s Board of Trustees and senior management visited India and Nepal in March. Officials of both countries hosted the visiting delegation.

India and Nepal are two key partners for CIMMYT. India’s relationship with CIMMYT began before the Green Revolution, and the world has benefited from the research products of this collaboration. CIMMYT also has maintained a long partnership with Nepal, where the National Agricultural Research Center (NARC) has hosted CIMMYT’s South Asia Regional Office for 18 years.

Field Visits in India

visitingNepalOn the first day of the field visits, about 200 farmers from nearby villages greeted the delegation and expressed appreciation for new practices that were helping them to diversity agricultural production and conserve resources such as water and soil. The delegation was welcomed in Kapriwas, Gurgaon by senior officials of the Indian Council of Agricultural Research (ICAR), including Director General Mangala Rai, Deputy Director of Crops and Horticulture G. Kalloo, and M.K. Miglani, Vice Chancellor of Haryana Agricultural University. They explained how new tillage and planting practices helped Indian farmers by saving labor, fuel, and irrigation, while maintaining or increasing yields.

Many farmers were extremely enthusiastic about the visit. One farmer was sprinkle irrigating wheat that was close to maturity, which is something that is not typically done. When one of the visitors asked why he was doing this, the farmer replied that he was overjoyed by their visit and wanted to show off his sprinkle irrigation system. (The technical explanation was that he wanted to lower the heat stress and improve grain filling.)

The visitors saw research to identify salt-tolerant wheat and other crops and to study the long-term effects of saline water use at Bawal Research Station. They also saw an experiment showing how paired-row wheat planting on beds produced high yields, large spikes, and large grains, which help wheat fetch a higher market price. Although all the farmers who joined the delegation agreed that wheat planted on beds in paired rows gives higher yields with less labor and fewer inputs, they said there is a shortage of bed planters for Indian farmers. CIMMYT, ICAR, and the private sector are working to improve the situation.

Another experiment they observed evaluated the potential for growing maize in Haryana, where limited production and high demand compel people to buy maize in Delhi or Rajasthan.

On the second day the delegation visited Durgapura Research Station of Rajasthan Agricultural University. They learned about a wide spectrum of research, including breeding for resistance to rust and to cereal cyst nematode and for tolerance to saline conditions. They heard about issues related to the use of brackish and saline water in crop production in arid regions. Some participants expressed concern about the long-term health effects of this practice, especially in the production of green vegetables.

On the third day the delegation was received by farmers of Kallogarhi-Matiala Village, as well as PP Singh (Vice Chancellor, Sardar Vallabh Bhai Patel University of Agriculture and Technology, Meerut) and Larry Paulson (USAID-India). Board members were very interested in locally developed, low-cost equipment for promoting conservation agriculture. They saw the comparative performance of wheat planted using zero-tillage drills with “inverted T” and double disc openers. Farmers at this site are developing a permanent “double no-till” system of conservation agriculture to grow rice and wheat.

During dinner, representatives of Raja Balwant Singh College Trust thanked CIMMYT for more than 50 years of partnership in Indian agricultural development, dating back to before the Green Revolution. They suggested that CIMMYT and RBS, the largest and one of the oldest agricultural colleges in India, could benefit from a joint visiting scientist program.

Field Visits in Nepal

In 2003, Nepal’s national average wheat yield surpassed 2 t/ha for the first time, an achievement that gives some idea of the constraints that farmers there have overcome. The National Wheat Research Program Coordinator, Mr. M.R. Bhatta, described the impact of disease and yield nurseries that CIMMYT and NARC distribute throughout South Asia, and observed that more than 20 wheat varieties have been released in Nepal in the past 15 years.

At Khumaltar Research Station, NARC researchers highlighted studies in areas such as pathology, breeding, agronomy, soil sciences, mechanization, and biotechnology.

The visitors also heard researchers from the Hill Maize Research Project describe how communities have become self-sufficient in maize, their staple food, for the first time. Nearly 80% of Nepal’s maize is grown in the mid-hills, where more than 10 million people depend on the crop for food, income, and animal feed. Shortages are chronic. The Hill Maize Research Project provides the farmers with source seed, plus training in seed production techniques, storage, and marketing. It also ensures that there is sufficient seed of new maize varieties for farmers to replace old improved or local varieties, which yield very little.

Through their efforts, communities have produced more than 150 tons of maize seed. Community-based seed production accelerates seed replacement, disseminates new technologies, improves household food security, and raises incomes. This work, supported by the Swiss Agency for Development and Cooperation (SDC), is having an enormous impact in isolated hill sites.

A visit to farmers’ fields in Thecho Village in the Kathmandu Valley showed how farmers’ access to better wheat varieties and growing practices was increasing through participatory research. The farmers partner with NARC, CIMMYT, the University of Bangore, the Agricultural Development Organization (ADO), and others in a project funded by the UK Department for International Development. Farmers enthusiastically shared their experiences with participatory variety selection and seed production. Some groups are earning enough additional income from growing wheat to purchase new equipment or make other investments.

NARC and ADO have extended participatory variety selection to rice, legumes, vegetables, and other crops throughout Nepal after seeing the success with wheat. (In India, similar exciting work is being done in collaboration with Banaras Hindu University.)

Thanks to Our Hosts

board_memberCIMMYT’s Board and staff are grateful to P.P. Manandhar, Nepal’s Secretary of Agriculture, and officials at the Ministry of Agriculture and Cooperatives for their constant support for CIMMYT’s South Asia Regional Office, and to NARC Executive Director R.P. Sapkota and his colleagues for support and field visits. They are also most grateful to ICAR Director General Mangla Rai, Deputy Director of Crops and Horticulture G. Kalloo, and the many representatives of experiment stations, colleges, and universities in India who made the visit a success. The opportunity to meet and visit the field with representatives of DFID, FAO, the Japan International Cooperation Agency, SDC, USAID, and the World Bank, among others, was also greatly appreciated.

We also thank the farmers who so kindly shared their experiences and hospitality with us.

Weighing Pros and Cons of Genetically Modified Crops in Africa

September, 2004

Should Africa embrace genetically modified crops to help feed its hungry people? That question is explored by a recent paper entitled “Debunking the Myths of GM Crops for Africa: The Case of Bt Maize in Kenya.” The paper compares the benefits of genetically modified crops to information available on the risks, and finds that most objections are not backed by evidence. Hugo De Groote, Stephen Mugo, and David Bergvinson from CIMMYT, along with Ben Odhiambo of the Kenya Agricultural Research Institute, conducted the study, which argues for a discussion based on scientific evidence and evaluation of potential benefits against concerns.

Genetically modified crops have been successful in many countries, including Canada and the US, where they have increased yields, lowered labor and cultivation costs, and reduced the use of chemical inputs. Genetic engineering has the potential to enhance food security and nutritional quality in ways not possible with conventional technology. Because the technology is contained in the seed, it is easy to distribute to farmers. This is particularly important in Africa, where extension services have largely collapsed and transport infrastructure is poor.

Concerns about deploying genetically modified crops in Africa include food safety, ethics, environmental risk, loss of landrace biodiversity, and the lack of appropriate biosafety regulations. Although long-term effects need to be analyzed, current studies by national and international organizations reveal no demonstrated toxic or nutritionally harmful effects of foods derived from genetically modified crops.

Sounding Out Public Opinion

The study by de Groote and his colleagues focused on Kenya, where maize, the main food crop, is planted on 30% of arable lands. It drew on a variety of data sources, including participatory rural appraisals and farmer and consumer surveys. De Groote thinks it is important to make research results understandable to the general public so everyone can participate in the debate.

To gauge awareness and attitudes about genetically modified crops, the researchers interviewed 604 consumers, only half of whom were aware of them. Many appreciated the benefits but worried about potential negative effects on health and the environment, especially on local plant varieties. De Groote says consumers are increasingly aware of genetically modified food and generally accept it, but their concerns about environmental safety and biodiversity have to be addressed.

Several seed companies in Kenya have expressed interest in producing and distributing Bt maize seed, which offers an effective and practical method for reducing stem borer damage in maize. Genetically engineered Bt maize contains a gene from the soil-dwelling bacteria Bacillus thuringiensis, which produces a toxin that helps control certain pests but is not harmful to humans or livestock. The Bt gene was first introduced into the commercial maize market in 1996. It has provided control for many pests and could help decrease pesticide use.

“The major surprise was that, contrary to the usual claims, Bt maize is very likely to benefit poor farmers and small seed companies,” says de Groote. “Stem borers are a real concern for farmers, especially in low-potential coastal and dry areas.”

Farmers in Kenya lose 400,000 tons, or about 14%, of their maize to stem borers. That is roughly the amount the country imports each year. De Groote says Bt maize alone will not solve this problem, but could help reduce losses and increase food security.

The IRMA Project

In 1999, the Insect Resistant Maize for Africa (IRMA) project was launched in Kenya to develop borer resistant varieties using both conventional breeding and biotechnology. Kenya already had experience with genetically modified crops and had biosafety policies in place. IRMA, a collaborative project between CIMMYT and the Kenya Agricultural Research Institute, receives financial support from the Syngenta Foundation for Sustainable Agriculture.

Before initiating the project, all parties involved agreed that transformed plants would carry only the gene of interest, without marker genes; that transgenic crops would only be developed for countries with appropriate biosafety regulations; and that only genes in the public domain would be used. They also agreed that the project would work under the highest scientific standards. When the project ends, other countries in Africa will be able to evaluate results from Kenya’s experience and decide for themselves which path to follow.

“I hope that the results will be accepted not only by the scientific community but also by the general population, in Africa as well as in the developed world,” says de Groote. “I also hope they will put to rest some of the major concerns about Bt maize for Africa.”

To make informed choices possible, the researchers contend that scientists in Africa need hands-on experience with the new technology. They need to test and adapt it using the appropriate regulatory framework and precautions. Further, the researchers believe that the technologies need to be developed in a participatory approach, since African farmers and consumers have the right to choose technologies based on the best knowledge available. They should not be denied the chance to improve their livelihoods as a result of an academic debate in which they are not included.

For more information: Hugo De Groote or Stephen Mugo

Ethiopia study on biofortified maize reveals tasty results

Quality protein maize can reduce or prevent stunted growth in young children, according to a recently published study.

nov02In eastern and southern Africa, maize is the least expensive and most prevalent cereal crop, but quantity cannot make up for quality. A maize-dominated diet helps keep bellies full, but does not provide a balanced diet. Specifically, maize lacks the essential amino acids lysine and tryptophan necessary for efficient protein synthesis. Quality protein maize (QPM)—a type of maize with increased levels of those two crucial amino acids—is the focus of a recent CIMMYT co-authored publication based on two studies conducted in separate locations in Ethiopia1.  The article delves into the role QPM can play in improving the nutritional status of young children in Ethiopia, where nearly 40% of children under five-years-old are underweight.

The first of the two studies ran from August 2002-03, in Wama Bonaya District, and showed that children who consumed QPM had a 15% increase in the rate of growth in weight over those who consumed conventional maize. The second study took place from October 2005-06 in the neighboring Sibu Sire District. Here, children fed a QPM diet had a growth rate in height 15% greater than that of children who ate conventional maize.

Both study sites were selected to represent high maize-producing and -consuming areas with high levels of child malnutrition. Sites were also selected based on environmental factors, such as rainfall and altitude, and for ease of operation for conducting the study. For almost all (97%) of the 341 participating households, farming was their sole occupation. Average farm size was 1.2 hectares. In both districts, maize was the dominant food for children—in Wama Bonaya  only 31% of families reported feeding their children foods other than maize, and in Sibu Sire 70% of the children regularly ate maize at least once a day. This highlights the vital role more nutritious maize could play in the future health and development of Ethiopian children.

Though there have been other studies on the effects and effectiveness of QPM (see Kernels with a kick: Quality protein maize improves child nutrition) this cumulative study varies slightly because it measures the effects of QPM when fully incorporated into the agricultural practices and home life of targeted households: study participants were given seed which they themselves grew and then prepared and consumed according to normal and locally-preferred practices, rather than being given pre-prepared QPM-based food products. This more closely mimics the impact QPM could have in a “real life” situation compared to some other previous study methods.

The study shows that although maize alone is not enough to sustain a nutrient-balanced diet, QPM can substantially improve the nutrition of children whose diets are, out of necessity, heavily based on one crop.

The paper was the result of collaboration among researchers Girma Akalu and Samson Taffesse of the Ethiopian Health and Nutrition Research Institute (EHNRI), Nilupa Gunaratna of the International Nutrition Foundation, and Hugo De Groote from CIMMYT-Kenya.

For more information: Hugo De Groote, agricultural economist (h.degroote@cgiar.org)

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Girma Akalu, Samson Taffesse, Nilupa S. Gunaratna, and Hugo De Groote. 2010. The effectiveness of quality protein maize in improving the nutritional status of young children in the Ethiopian highlands. Food and Nutrition Bulletin, 31(3): 418-430.

No maize, no life!

CIMMYT E-News, vol 6 no. 4, June 2009

In Morogoro, a drought-prone area in Tanzania, farmers are using certified maize seed and urging other farmers to grow a new drought tolerant variety, TAN 250, which they say is like “an insurance against hunger and total crop failure, even under hot, dry conditions like those of recent years.”

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Wheat farmers see infrared

CIMMYT E-News, vol 4 no. 7, July 2007

jul03Infrared sensors help better target fertilizer for wheat on large commercial farms in northern Mexico, cutting production costs and reducing nitrogen run-off into coastal seas.

Farmers of the Yaqui Valley, Sonora State, northern Mexico, and fish in the Sea of Cortez: what ties could they possibly share? Well, if CIMMYT wheat agronomist IvĂĄn OrtĂ­z-Monasterio and fellow researchers at Stanford University and Oklahoma State University achieve their aims, both farmers and fish may breathe a little easier.

OrtĂ­z-Monasterio and his partners have been testing and promoting with Yaqui Valley farmers a sensor that measures light reflected from wheat leaves and thereby gauges the health and likely yield of the plants. The device is calibrated to capture red wavelengths, which indicate chlorophyll content, and infrared wavelengths, a measure of biomass. The readings are run through a mathematical model to provide a recommendation about whether or not the crop requires a mid-season application of fertilizer.

Yaqui Valley wheat farmers work large holdings (averaging around 100 hectares), use irrigation and mechanization, and grow improved varieties with fertilizer, fungicides, and other inputs. They typically get excellent yields—on the order of 6 tons per hectare. Despite this, they are feeling squeezed by the rising costs of diesel fuel, water, fertilizer, and other inputs, and many are actually in debt; so they are fervently seeking ways to save money.

Too much of a good thing?

“Farmers here typically apply 230 kilograms of nitrogen per hectare, and 150 kilograms of this goes on 20 days before sowing,” explains Arturo Muñoz Cañez, a consulting agronomist who works a lot of the time with the AsociaciĂłn de Organismos de Agricultores del Sur de Sonora, an umbrella group that includes seven farmer credit unions serving producers on some 140,000 hectares in the region. “Our studies with IvĂĄn have shown that local wheat crops actually use only about one-third of that fertilizer.”

Where does the rest go? Some evaporates into the atmosphere, in the form of nitrous oxide, a notorious greenhouse gas that is nearly 300 times more damaging than carbon dioxide. Another part leaches as nitrate into groundwater, and much of the rest dissolves in run-off irrigation and rainwater, eventually finding its way to the west coast of Sonora and into the sea. There it may fertilize oxygen-hungry algae that can suffocate other marine life and cut into fishermen’s catches.

From Mexico to the world

jul04
With the help of OrtĂ­z-Monasterio, Muñoz, and other agronomists, Yaqui Valley farmers used the sensor on 174 plots in 2006-07, comparing readings from a fully-fertilized comparison strip with those from the rest of the field at 45 days after sowing—a point at which most important differences in crop development are evident. They then followed the resulting recommendations concerning how much additional fertilizer was needed, if any. In 66% of the cases, the recommendation was to apply nothing more. At harvest, yields from both the fully-fertilized strips and 86 test plots were compared by weighing the grain. “92% of the farmers got good yields—that is, comparable to those of fully-fertilized strips—and on average saved around US$ 75 per hectare in fertilizer they did not apply,” says Muñoz. That’s a US$ 7,500 savings for a 100-hectare farm.

Ortíz-Monasterio attributes the success partly to residual fertility in the local soils, but would like to see eventual adoption of more precise, resource-conserving agricultural practices—including direct seeding without tillage, retaining crop residues on the soil surface, and improved water use efficiency—on at least half of the total 200,000 hectares of the Yaqui and nearby Mayo Valleys. “The Yaqui Valley has been a sort of laboratory for the rest of the world,” says Ortíz-Monasterio, who has worked for several years with researchers in Pakistan to adapt the sensor for the country’s extensive irrigated wheat lands. “A lot of what was first developed here—high-yielding wheat varieties, sowing on raised beds, and now the sensor—has gone on to be used in other wheat farming regions of the developing world. In some ways, what happens here is a reflection of how successful or not CIMMYT is.”

Ortíz-Monasterio is also promoting a lower-cost alternative for farmers who may not be able to work with a sensor: “You simply establish a well-fertilized strip in your field. If the rest of your crop looks comparable in health and development to plants in the strip, then you don’t need to apply more fertilizer. If there is any difference, then you apply what you would normally apply. In this way, we’d help at least half the irrigated wheat farmers in the world.”

For more information: IvĂĄn OrtĂ­z-Monasterio, wheat agronomist (i.ortiz-monasterio@cgiar.org)

Molecular detection tools for African maize breeders

CIMMYT E-News, vol 3 no. 1, January 2006

MolecDetectionA new DNA detection service provided by CIMMYT and KARI responds to African researchers’ calls for modern technology.

African maize breeders now have access to state-of-the-art biotechnology tools thanks to a service launched by CIMMYT and the Kenya Agricultural Research Institute (KARI). Housed within the laboratories at the International Livestock Research Institute (ILRI) headquarters in Nairobi, under the Canadian International Development Agency (CIDA)-funded Biosciences Eastern and Central Africa (BECA) platform, the lab offers and trains researchers in the use of molecular marker techniques.

The molecular markers are DNA snippets that help researchers locate and select for genes associated with traits of interest, including resistance to pests and diseases, or tolerance to stresses like drought. With markers, breeders can cut the time and money needed to develop plant types that possess such useful traits. Until now, this capability had been unavailable to scientists in sub-Saharan Africa, outside of South Africa.

Led by CIMMYT biotechnologist Jedidah Danson and supported by the Rockefeller Foundation, the service now has its hands full of requests from breeders working with CIMMYT, national agricultural research systems, local seed companies, and universities. “They’ve learnt of the service entirely through word-of-mouth,” she says. “It’s especially attractive because current funding allows us to offer the service free, so more breeders are exposed to the technology.”

Breeders using the service are especially interested in finding ways to incorporate resistance to maize streak virus, a disease endemic in much of sub-Saharan Africa and in enhancing the nutritional quality of herbicide tolerant maize, originally developed as part of a package to control the parasitic witch weed.

“Marker assisted selection is an important tool for breeders in Africa. CIMMYT and KARI must be lauded for being the first in the region to provide the service to public sector researchers,” says Richard Edema, molecular breeder at Makerere University, Uganda. Edema is also coordinator of the African Molecular Marker Application Network, a consortium of about 100 biotechnologists and breeders from across sub-Saharan Africa.

Danson is building a database of markers for genes for resistance to important pests and diseases, including maize streak virus, gray leaf spot, the parasitic weed Striga, and northern corn leaf blight. She also helps train breeders in the effective use of markers. “Clearly, our partnership to support African breeders was long overdue,” she says.

For more information contact Jedidah Danson (j.danson@cgiar.org)

Winning in the long run

CIMMYT E-News, vol 3 no. 12, December 2006

Three decades of research into drought tolerant maize by CIMMYT and a very strong set of partnerships has made a difference in the lives of African farmers. That achievement has been recognized by the awarding to CIMMYT of the 2006 CGIAR King Baudouin Award.

It began with a small experiment to try to improve the lowland tropical maize population called Tuxpeno for drought tolerance in Mexico in the1970s. The United Nations Development Program (UNDP) started to invest in more significant research around drought tolerant maize in 1986. In the mid-1990s, the focus of the work moved to Africa—to the most challenging maize growing environments world-wide: southern and eastern Africa, where maize is a source of food and livelihoods for some 250 million people.

Today, sufficient seed has been produced to plant over 2.5 million hectares of land in eastern and southern Africa with new varieties that produce more maize both when dry spells occur and under good conditions. The road in-between involved the building of a large partnership with donors, national agricultural research programs, extension programs, small-scale seed producers, community seed producers and individual farmers; developing new ways of screening germplasm in real world conditions; and enhancing farmer-participatory methods to select the best and disseminate the best.

CIMMYT and its partners employed novel methodologies in breeding that were pro-poor according to Marianne BĂ€nziger, the director of CIMMYT’s Global Maize Program.

“Traditional varieties have been developed with fertilizer applied under good rainfall conditions. CIMMYT took a completely different route,” she says. “We took the varieties; we exposed thousands of them to very severe stress conditions—drought, low soil fertility. We selected the best. We brought them to farmers and farmers told us which ones they liked.”

The projects invested in over 25 fully-equipped managed-stress screening sites and more than 120 testing sites owned and operated by national programs. A network was established involving CIMMYT, public National Agricultural Research Systems (NARSs), and the private sector to systematically test new varieties and hybrids from all providers for the constraints most relevant to smallholder farmers in eastern and southern Africa. This network recently provided proof that the stress breeding approach works. In a simple comparison between all maize hybrids from CIMMYT’s stress breeding approach and a similar number of hybrids developed by reputable private companies using the traditional approaches—using 83 hybrids, 65 randomly-stressed locations across eastern and southern Africa, and 3 years of evaluation—the results demonstrated that, under production circumstances most similar to those of resource-poor farmers in Africa (that is, at yield levels of 1–5 tons per hectare), the CIMMYT varieties yielded on average 20% more in the most difficult conditions and 5% more under favorable conditions. Among these the best stress-tolerant hybrids increased yields as much as 100% under drought, showing the great potential contained in maize genetic resources.

The final selection was done through a participatory methodology called the “mother-baby” trial system, in which farmers managed some “baby” plots in their own fields while NGOs, researchers and extension staff conducted a “mother trial” in the center of their community. This way farmers could see how potential varieties actually performed under local conditions.

As a result, more than 50 open-pollinated and hybrid varieties have been disseminated to public and private partners, NARSs, NGOs and seed companies, for seed production and dissemination to farmers. “None of this success would have been possible without the collaboration of many dedicated researchers, NGO and extension staff from the public and private sector.” says BĂ€nziger. “They were the ones evaluating varieties under diverse conditions with farmers. They also started to adopt the new breeding methods in their own programs, developing their own varieties, engaging in seed production and tackling the challenge of getting seed to farmers.”

The story is not finished. CIMMYT researchers are sure the genetic diversity in maize is sufficient to push the drought tolerance in new maize varieties significantly further. “Yield gains are such that with every year of research we can add another 100 kg of grain under drought,” says BĂ€nziger. The greatest challenge is to incorporate these gains into adapted varieties and get the seed to the farmers who need it most—a tremendous task and opportunity given the looming threats of climate change.

For more information, Marianne BĂ€nziger (m.banziger@cgiar.org)

“Hot spots” in Maize for Dry Regions in the Developing World

CIMMYT E-News, vol 2 no. 10, October 2005

hotspotA new genomic map that applies to a wide range of maize breeding populations should help scientists develop more drought tolerant maize.

Throughout the developing world, drought is second only to soil infertility as a constraint to maize production, and probably reduces yields worldwide by more than 15 percent (more than 20 million tons) annually. Lines have now been drawn on a new battleground: a map of the chromosomes that shows important areas that help maize resist drought.

Of the world’s three most important cereal crops (rice, wheat, and maize), maize has the most complex genetic structure. As maize has been bred and adapted to many different growing environments, selection has produced a crop that contains significant differences in levels of genetic diversity. But many genes and genetic sequences should be the same or similar. Scientists are hopeful that genetic traits for drought tolerance can be found in such shared genomic sections, across a wide range of tropical maize types. A new consensus map of genes across maize populations may be the key to identifying universal genetic “hot spots,” those genomic regions that confer drought tolerance in diverse settings to varying degrees.

hotSpot2
“Are there any regions in the maize genome that come out as ‘hot spots’?” Jean-Marcel Ribaut and his team have asked. Known to scientists as quantitative trait loci (QTL), these regions tell scientists approximately where the genes determining a particular plant trait are located. The QTL is not a gene itself but a genomic region in which genes of interest are probably located. Prior genomic maps of QTLs for drought tolerance in tropical maize applied only to specific maize lines or populations. The CIMMYT team and partners have developed a single map that combines available drought QTL data from many trials of different tropical maize types in diverse environments. “Having all the QTL information integrated into a single map should allow us to identify the outstanding genomic regions involved in drought tolerance,” Ribaut says.

Scientists have measured drought related traits such as ear number, chlorophyll, and carbohydrate content of maize plants in the field, and have extracted and analyzed DNA from the same plants in order to plot the traits on the genomic maps. Ribaut, now Director of the Generation Challenge Programme, and CIMMYT molecular geneticist Mark Sawkins hope to link the traits they measured in the field with regions in the maize DNA.

“The idea is ambitious,” says Ribaut, “for it should allow maize breeders to select the right parents for drought tolerant maize by ensuring they have these important regions on their genome.”

With funding from the Rockefeller Foundation, members of the project team will give courses on this approach in to NARS scientists in Kenya and China over the coming months.

For further information, contact Jean-Marcel Ribaut (j.ribaut@cgiar.org) or Mark Sawkins (m.sawkins@cgiar.org).