research: Genetic resources

New Maize from CIMMYT: No “Throw-away” Lines!

Written by on May 14, 2012. Posted in Features.

CIMMYT E-News, vol 2 no. 12, December 2005

newMaize New, elite maize lines from CIMMYT offer enhanced nutrition and disease resistance.

CIMMYT has just released two unique maize lines that will interest breeders in developing countries. One is the first to combine maize streak virus resistance in a quality protein maize and the other is a quality protein version of one of CIMMYTs most popular maize lines. Made available every few years to partners, CIMMYT maize lines (CMLs) are among the most prized products of the Center’s maize breeding program.

“These are truly elite maize lines,” says Kevin Pixley, the Director of the Center’s Tropical Ecosystems Program. “They represent a distillation of maize genetic resources from around the world to which CIMMYT, as a global center, has privileged access. Only one of 10,000 lines might become a CML. Breeders in national programs in many developing countries look forward to new sets of these lines.”

The lines are inbred and possess excellent combining ability, which means they can be used to form either hybrids or open pollinated varieties, and so are versatile parent materials for breeders in national programs.

The new quality protein and maize streak resistant line will serve as a natural replacement for a parent in the popular Ethiopian maize hybrid, Gabisa. Maize streak virus is endemic in Africa. Severely infected plants do not produce proper cobs and nor grow to full height. Farmers will have the chance to use a hybrid with the enhanced nutritional characteristics of quality protein maize, plus built-in disease resistance.

The quality protein version of one of CIMMYT’s most successful maize lines—CML264—is virtually indistinguishable from the original parent, which is found in the pedigrees of more than a dozen commercial hybrids in Central America, Colombia, Mexico, and Venezuela. Farmers using varieties derived from it will obtain the same high yields as always, while enjoying the higher levels of grain lysine and tryptophan—two essential amino acids that improve nutrition for both humans and farm animals.

A description of the complete set of new CMLs can be found at:
https://data.cimmyt.org/

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

Danish Environment Ministers and Parliamentarians Visit CIMMYT

Written by on May 14, 2012. Posted in Features.

March, 2004

Denmark’s Minister for the Environment, Hans Chr. Schmidt, and members of the Environment Committee of the Danish Parliament came to CIMMYT on 4 March for a briefing on the role of agriculture and research in development, the conservation and study of genetic diversity, the potential of biotechnology, and biosafety issues. They were accompanied by Søren Haslund, Ambassador of the Government of Denmark to Mexico. During their visit they were joined by Lisa Covantes, representative of Greenpeace-Mexico.

The briefing ended with a short tour of CIMMYT’s laboratory, greenhouse, and genebank facilities. In the laboratory, researchers described how biotechnology tools increasingly facilitate the study and use of genetic resources. As one example, they presented a “maize family tree” developed on the basis of genetic analyses that assess the extent to which maize varieties and races from throughout the world are genetically similar or quite distinct. The visitors saw transformed maize and wheat plants growing in the biosafety greenhouse. In CIMMYT’s genebank, where some of the world’s largest collections of maize, wheat, and related species are held in trust for humanity, the visitors learned how these genetic resources are used to develop new varieties. They heard about CIMMYT’s work in Mexico to understand how traditional farmers manage maize diversity on the farm, and then visited one of the cold storage vaults where seed is kept.

Denmark is a world leader in its strong and thoughtful commitment to reducing poverty in developing countries through economic growth and environmentally sustainable development. The visit of the Danish delegation provided a welcome opportunity to exchange views on the role of public agricultural research for development.

The visiting members of the Environment Committee of the Danish Parliament included Eyvind Vesselbo, Mogens Nørgård Pedersen, Torben Hansen, Jørn Dohrmann, Elsebeth Gerner Nielsen, Keld Albrechtsen, Helge Mortensen, Lone Møller, Jacob Buksti, Inger Bierbaum, Jens Vibjerg, Helga Moos, Søren Gade, Gudrun Laub, Freddie H. Madsen, and Inger Støjberg.

1) From left to right: Eyvind Vesselbo, Minister Schmidt, and Director General Iwanaga
2) Minister Schmidt and Eyvind Vesselbo in the briefing room
3) Visiting the biotech lab
4) Visiting the genebank

Gene Flow Study Explores How Farmers Keep Maize Thriving and Changing

Written by on May 14, 2012. Posted in Features.

June, 2005

gene_photo1 What role do farmers play in the evolution of maize diversity? How extensive are the farming networks and other social systems that influence gene flow? These and other questions are helping researchers to combine knowledge of the genetic behavior of plants with information on human behavior to understand the many factors that affect maize diversity.

Outside a straw and mud-walled house in rural Hidalgo, Mexico, with chickens walking around and the smell of the cooking fire wafting through the air, CIMMYT researcher Dagoberto Flores drew lines with a stick in the red earth as he explained to a farmer’s wife how maize seed should be planted for an experiment. Along with CIMMYT researcher Alejandro Ramírez, Flores was distributing improved seed in communities where they had conducted surveys for a study on gene flow.

The movement of genes between populations, or gene flow, happens when individuals from different populations cross with each other. CIMMYT social scientist Mauricio Bellon is leading a study that aims to find out the impact of farmers’ practices on gene flow and on the genetic structure of landraces. It will document how practices differ across farming systems, analyze their determinants, figure out how much farmers control gene flow, and explore gene flow’s impacts on maize fitness and diversity and on farmers’ livelihoods.

gene_photo2 The farmers visited by Flores and Ramírez in early June near Huatzalingo and Tlaxcoapan, Hidalgo are from just 2 of 20 study communities spanning ecologies from Mexico’s highlands down to the lowlands. Six months earlier, when farmers in these communities responded to researchers’ survey question, they asked some questions of their own: What does CIMMYT do? How can we get seed?

The team made it a priority to give the farmers what they requested for free. They drove around in a pick-up truck with seed they had acquired from CIMMYT scientists. They brought black, white, and yellow varieties that were native to the area and had been improved with weevil and drought resistance, and they also brought three CIMMYT varieties that were well adapted to a similar environment in Morelos, Mexico. They explained to the farmers how each variety should be planted in separate squares to facilitate pure seed selection.

“It’s a way to thank them, to bring something back to the communities,” says Bellon. Bringing improved germplasm for experimentation to interested small-scale farmers also allows researchers to get feedback in a more systematic way. The farmers will produce the maize independently, and they can save or discard seed from whichever varieties they choose. The team also distributed seed to farmers in Veracruz, and they plan to return after flowering and at harvest time to see how the improved seed fares compared with native varieties. That component of the project could be the beginning of further research in collaboration with farmers.

gene_photo3 Farmers in the survey area of rural Hidalgo grow maize on the poorest, most steeply sloping land and struggle with soil diseases, low soil fertility, leaf diseases, low grain prices, and limited information about the use of chemical herbicides. Strong wind, rain, and hurricanes damage crops. Landslides cause erosion. Some farmers have access to roads and can transport their harvest by vehicle, but some farms located far from the communities have no highway access. The paths to farmers’ fields can be so narrow that not even cargo animals can maneuver on them with loads, so farmers must carry the harvest on their backs. Some walk 10 kilometers up and down slopes with heavy bags on their backs.

Many people grew coffee around Huatzalingo until about 10 years ago when the price plummeted. A kilogram of coffee used to fetch a price of about 20 pesos, or US$ 2. Now it fetches about five pesos, or 50 cents, per kilo, and even less during harvest time when the crop is abundant. Coffee producers in the area receive average government subsidies of between 125 and 300 pesos, or between US$ 10-30. One effect of the price drop has been increased immigration to Mexico City, to the city of Reynosa near the US border, and to lowland areas where orange cultivation is booming.

Partly in response to the crisis, farmers have started diversifying into alternative crops such as vanilla, citrus fruits, bananas, sugar cane, sesame, beans, chayote, chili peppers, and lentils, but the poor soils do not favor more lucrative crops. Maize is still the most important agricultural product in people’s diets in this area, and farmers grow it primarily for family consumption. They exchange seed with friends, neighbors, and producers in nearby communities, and they have conserved diverse native varieties.

In Mexico, maize has such great genetic diversity because farmers’ practices encourage the further evolution of maize landraces. Maize was domesticated about 6,000 years ago within the current borders of Mexico. Farmers created a variety of races to fit different needs by mixing different maize types, and they still experiment like that to this day. They save seed between seasons and trade seed with each other, and the wind carries pollen between different cultivars to create new mixtures.

“They are not artifacts in a museum,” Bellon says about landraces. “They are changing, they are moving.” Seed selection has a great impact on gene flow. Poor farmers typically exchange seed with each other, but little has been documented about the social relations that drive seed systems. With growing concerns about a loss of crop genetic diversity and a need to conserve genetic resources in recent years, it is important to understand the social principles of seed flow (and ultimately gene flow) in Mexico. The study findings will assist in exploration of the potential impact of transgenes. The researchers will develop models to try to predict how a transgene would diffuse and behave after it has been in a population for 10 or 20 years.

By learning about the relationships between farmers’ practices and gene flow, researchers hope to promote more effective policies regarding the conservation of diversity in farmers’ fields, the distribution of improved germplasm, and transgene management. Funded by the Rockefeller Foundation, the study combines social science with genetics to connect social and biological factors in maize varieties. Molecular markers will help show how much gene flow has occurred over time between the Mexican highlands and lowlands.

Researchers used geographic information systems to choose varied environments for the survey. Starting in October 2003, they sampled maize populations and interviewed the male and female heads of 20 households in each community for a total of 800 intensive interviews in 400 households. They asked about topics such as principal crops, planting cycles and methods, maize varieties, machinery and tools, infrastructure, language, seed selection, fertilizer, pest and weed control, plant height, harvest, transportation, production problems, maize uses, the sale and demand of different varieties, knowledge about maize reproduction, husk commercialization, and level of migration.

Preliminary findings have already surprised Bellon. A growing market for maize husks, which are used to wrap traditional foods such as tamales, is changing the economics of maize production. Owing to increasing demand from the US, husks have become more commercially important and profitable than grain in some communities. Facing abysmally low grain prices, the success of husk production has caused some producers to seek maize varieties with high quality husks, almost regardless of grain quality.

Bellon was also surprised at the lack of improved varieties in the areas they studied. Farmers tended to seek out and plant native varieties instead of hybrids. Some farmers thought hybrids were expensive, produced poor quality husks, and required good land, chemicals, and fertilizer, but they thought native varieties adapted easily to marginal local conditions.

The study grew out of a six-year project in Oaxaca that examined the relationship between farmers’ practices and the genetic structure of maize landraces and seed flow among farmers. It also explored the implications of transgenic technologies. However, while the Oaxaca project examined a few communities located in one environment, the idea with this follow-up study was to examine many locations in the same and different environments. In that way researchers can find out if gene flow is localized or if it crosses between regional environments. “It’s the same research model on a broader scale,” says Bellon.

For information: Mauricio Bellon

The genetic revolution continues at CIMMYT

Written by on May 14, 2012. Posted in Features.

CIMMYT E-News, vol 4 no. 8, August 2007

Faster, cheaper, more efficient: gift from DuPont helps CIMMYT scientists look for genes in wheat and maize—and gives breeders an affordable tool to help select the best.

aug07 A quiet revolution is taking place in CIMMYT’s biotechnology labs. The team has just received a new generation of genotyping machines. These semi-automated work-horses will make it much easier to determine whether breeding lines contain specific useful genes. It is hoped that this will help maize and wheat breeders—through a process known as marker-assisted selection (MAS)—to make breeding more effective and get crop varieties with valuable traits to poor farmers more quickly.

Traditionally, the only way to find out whether the offspring from a particular cross have inherited useful characteristics, such as drought tolerance, disease resistance, or grain quality, has been to grow them in the field and evaluate the adult plants. MAS can speed up the breeding process, since it makes it possible to track the presence of desired genes in every generation. This does not bypass the need for field evaluation, but can greatly improve the efficiency of the process. “Field screening takes time, space, and resources, and our capacity is limited,” explains CIMMYT maize breeder Gary Atlin, “but with MAS we could use resources more effectively, zeroing in on the best lines to test in the field and filtering out those that haven’t inherited the characteristics we need.”

When researchers want to find out whether a particular line of wheat or maize has the useful version of a gene (for example, disease resistance rather than disease susceptibility), they use nearby, identifiable sections of DNA known as markers, labeled with a fluorescent dye. Different versions of markers and genes are called alleles. DNA that is close together on the chromosome tends to stay together over generations, so a specific allele of a marker will be routinely inherited alongside the desired allele of a nearby gene. Using the new capillary electrophoresis genotyping machines, the sample is forced along a narrow capillary tube under the influence of an electric current. A laser at the end of the tube detects the different alleles of the fluorescent markers, indicating to the scientist whether the sample contains the allele they want.

aug08 The two ABI 3700 machines have been generously donated to CIMMYT by DuPont through its Pioneer Hi-Bred seed business, reflecting a fruitful collaborative relationship of more than a decade’s standing. Until now, CIMMYT has run most of its marker-assisted selection work on manual, gel-based electrophoresis apparatuses. In addition, analyses of genetic relationships between different wheat or maize lines have been run on older ABI genotyping machines, including two based on the previous, much slower generation of gel-based machines. The new machines can handle many more samples—96 each at a time—but it’s the savings in hands-on time that makes the real difference. “There’s no comparison,” says Marilyn Warburton, Head of CIMMYT’s Applied Biotechnology Center. “It will take us ten minutes to load one of these new machines, whereas it takes about four hours to make and load a manual electrophoresis gel.”

As well as being much quicker and less labor-intensive, capillary electrophoresis makes it possible to test for more than one marker and run more than one sample at once in each tube. By using different colors of fluorescent dye for each sample, markers for each can be distinguished, like teams of runners wearing different-colored jerseys. For maximum efficiency, scientists can also set up groups of samples to run at slightly different times, like runners set off in a staggered start. CIMMYT will even be able to develop a new type of marker, known as SNPs, which allow numerous traits to be tested simultaneously, providing more information per sample.

All of this means that the new machines have a much higher throughput capacity, and can process many more samples for the same labor input, drastically reducing the per-sample cost—currently the major constraint on use of MAS. “If MAS were significantly cheaper, I would certainly use it in maize breeding,” says Atlin. “Effectively, it lets you quickly transfer the genes you want into improved varieties. If you’re doing a backcross between a donor with a desired trait and an improved parent with good agronomic performance, you’re trying to select for one characteristic from the donor, but against all its other genes. With a number of markers, MAS makes it possible to determine exactly which progeny combine the desired gene from the donor with the good genes from the other parent. You can get results in two generations, compared to four or five normally.”

The challenge for MAS is finding genes with substantial effects, especially for complex traits such as drought tolerance in maize. Atlin believes such genes are still to be found. “In the past, donors with a single useful gene or trait but otherwise poor agronomic qualities were very difficult to use in breeding, as they introduced so much bad material. We can get rid of that useless material through MAS. That opens up the field to look for useful genes in a wider range of parents. And genotyping technology is getting cheaper and better at finding genes all the time.”

In wheat, the hunt for useful markers at CIMMYT is more advanced. “We’re working with new markers to select for nematode resistance, leaf and stem rust resistance, boron tolerance, Fusarium resistance, and grain quality,” says Susanne Dreisigacker, CIMMYT wheat molecular biologist. “Our current work is all gel-based, which means running tests sample by sample and marker by marker. Being able to run many samples at the same time will make a huge difference.”

For more information: Marilyn Warburton, molecular geneticist (m.warburton@cgiar.org)

New Japan–CIMMYT Project Hunts for Genes to Fight Disease

Written by on May 14, 2012. Posted in Features.

June, 2004

No single strain of wheat, barley, or related species completely withstands Fusarium Head Blight, a disease that is making increasing inroads on health and harvests worldwide. A new project offers better methods and broader gene pools for finding genes to ward off the disease.

Fusarium Head Blight (FHB), one of the most destructive wheat diseases in warm and humid regions, seriously threatens wheat and barley production around the world. Even worse, the toxins produced by Fusarium fungus cause acute food poisoning in people and harm animals that eat infected grain.

A new five-year-long collaborative project between CIMMYT and the government of Japan aims to discover genes that control FHB resistance, identify wheat germplasm that can be used in FHB resistance breeding programs, and develop FHB resistant wheat by using DNA markers.

Scientists in Japan began conducting genetic and breeding studies on FHB resistance in the 1960s, after an epidemic swept across more than 400,000 hectares in 1963 and caused estimated yield losses of more than 50%. More recent epidemics in 1996 and 1998 affected about 26% of the land in Japan. Developing countries also suffer losses from FHB, and CIMMYT started its own breeding program on FHB resistance about 20 years ago.

In the United States, FHB is the worst plant disease to emerge since the 1950s, according to the United States Department of Agriculture. In the 1990s, epidemics in seven US states caused more than US$ 1 billion in crop losses. Partly due to climate changes caused by global warming and the increased use of reduced tillage practices, FHB has become more widespread in recent years.

Sources of resistance to the disease have been elusive. Researchers have never found an accession of wheat, barley, or their wild relatives that is completely immune to FHB, according to Tomohiro Ban, a scientist at Japan International Research Center for Agriculture Sciences. A lack of good sources of resistance and good methods for finding them prompted the government of Japan to fund the new project with CIMMYT, which Ban is now leading at CIMMYT-Mexico.

The genetic constitution and chromosomal location of FHB resistance genes are not well known, but current research suggests that several quantitative trait loci or minor genes control resistance. DNA markers could identify and evaluate these genes. It is hoped that the project’s search for resistance genes will also advance because of access to CIMMYT’s genebank, which has one of the world’s largest collections of wheat and its wild relatives. Researchers will be able to screen materials from a great diversity of gene pools and environments.

“We are going to use the untapped potential of these diverse genetic resources and find new sources of resistance,” says CIMMYT Director General Masa Iwanaga. Even more important, the program could become the focus for a more organized worldwide effort to combat the disease. “We would like to facilitate a platform for international collaboration, because this is a global problem,” comments Iwanaga.

For information: Tomohiro Ban

SIDU + ISO = Quality assured

Written by on May 14, 2012. Posted in Features.

CIMMYT E-News, vol 4 no. 4, April 2007

apr04 The Seed Health Laboratory, part of CIMMYT’s Seed Inspection and Distribution Unit (SIDU) has become the first in the Consultative Group on International Agricultural Research (CGIAR) to gain International Organization for Standardization (ISO) certification

For the past 10 months there has been a little extra edge at the Seed Health Laboratory at the CIMMYT campus in El Batán, Mexico. Everything every researcher and technician did when handling maize and wheat seeds was being scrutinized in the minutest detail by inspection teams from the Mexican Accreditation Entity (EMA) for the ISO. “It was sometimes tense, but I knew our procedures were already at a high level, so I wasn’t really worried,” says Monica Mezzalama, head of SIDU.

The routine shipment and reception of maize and wheat seed samples is the life blood of a global breeding center like CIMMYT. Its crop improvement research means breeding new types of seed that can enhance the livelihoods and food security of farm families in the developing world. You can improve all the seed you want at an experiment station, but eventually you have to ship seed for testing by farmers and national research programs outside of the country where the breeding was done. Also, given that CIMMYT holds the world’s largest collection of maize and wheat germplasm in trust in its genetic resources center, each year it sends hundreds of shipments of seed from those stores to breeders and other researchers from around the world, in response to their requests for samples.

Seed can carry pathogens—viruses, bacteria, or fungi—that reduce the viability of the seed itself or prevent the plants from growing well. When seed is consumed directly as food or feed, seed-borne organisms may cause chemical changes, degrade seed contents, or release powerful toxins that can harm humans and livestock. In the best of cases, food is simply wasted; in the worst, famine or poisoning can result. Certain seed-borne pathogens are endemic to specific areas of the world; great efforts are made to confine them and not allow their spread.

apr05

In 1989 CIMMYT established an independent Seed Health Laboratory and in 2004 the seed inspection and distribution unit (SIDU) to handle the inspection and shipment of seed, essentially ensuring that no seed with disease pathogens on board enters the center’s breeding programs or leaves its premises for other destinations. All CGIAR research centers with crop genetic resource collections produce and distribute seed from breeding trials or from their genebanks. All maintain their own, stringent standards and have shared their experiences. Until recently, seed health standards at CIMMYT were self-imposed, in cooperation with the government of Mexico. The implementation of free trade agreements between Mexico and other countries—particularly the USA and Canada—brought a commitment from Mexico to ensure that all seed originating from the country conformed to international norms.

The ISO is the world’s largest developer of standards. ISO standards have important economic and social repercussions, making a positive difference not just to organizations for whom they solve basic problems in production and distribution, but to society as a whole. Mexico adopted ISO standards for seed movement, to be administered by EMA. For CIMMYT it is the ISO/IEC 17025-2005 General requirements for the competence of testing and calibration laboratories. “We knew all along that our seed health procedures were the best,” says Masa Iwanaga, CIMMYT Director General. “But having the toughest outside inspection in the world confirm what we knew is very gratifying, not only for us but for our partners in more than an hundred countries.”

More information Monica Mezzalana, Head, SIDU (m.mezzalama@cgiar.org).

CIMMYT–China Wheat Quality Conference Highlights 10 Years of Collaboration

Written by on May 14, 2012. Posted in Features.

June, 2004

iwqc_group
Which food crop is traded in larger quantities than any other in the world? The answer is wheat, and China produces more of it than any other country. With more than 150 participants from 20 countries in attendance, CIMMYT and China held their first joint wheat quality conference in Beijing from 29 to 31 May. The conference focused on progress in China’s wheat quality research, educated participants about quality needs of the milling industry and consumers, and promoted international collaboration.

In recent years, advanced science has been making wheat more nutritious, easy to process, and profitable. Scientists can improve quality characteristics such as grain hardness, protein content, gluten strength, color, and dough processing properties. Quality improvement, however, is not an objective, one-wheat-fits-all-purposes kind of business. Wheat end products vary by region and require grain with different characteristics. For example, 80% of wheat in China is used for noodles and dumplings, but the desired wheat quality for those products might not be appropriate for pasta in Italy or couscous in North Africa.

“You can see a wide variation of wheat use reflecting cultural influences over many centuries,” says CIMMYT Director General Masa Iwanaga, who gave a keynote presentation at the conference about the benefits of adding value to wheat to improve the livelihoods of poor people. Iwanaga says he is impressed by China’s wheat quality research and emphasis on biotechnology in recent years.

Participants from major wheat producing regions such as China, Central Asia, India, the European Union, Eastern Europe, the United States, and Australia presented updates on a variety of topics related to the global wheat industry and quality management. The participants included experts in genomics, breeding, crop management, cereal chemistry, and the milling industry, among others.

The US, Australia, Canada, and the EU see Asia as a good market for their wheat, says Javier Peña, head of industrial quality at CIMMYT. Asian foods such as noodles have been becoming more popular in the west, says Peña, while traditional western wheat-based foods have been gaining popularity in Asia. The milling industry has been growing to meet this increasing demand. “It was evident that globalization is influencing consumers’ preferences,” he says.

Conference participant and CIMMYT wheat breeder Morten Lillemo thinks the organizers did a good job assembling top lecturers to provide information. Chinese wheat breeders have been paying a lot of attention to improving quality, he says, and participants now understand the characteristics that traditional Chinese end products require.

“China is the largest wheat producer in the world, but the quality of their wheat is highly variable, even for traditional products like steamed bread and noodles,” says Lillemo. “For me it was most interesting to learn about the wheat quality work going on in China, which challenges they have, and how they are dealing with them.”

The 10-year-long CIMMYT–China collaboration has been fruitful. Chinese wheat has been used to develop new varieties with Fusarium and Karnal bunt disease resistance, high yield potential, and agronomic traits such as lodging resistance and rapid grain filling. In turn, CIMMYT has helped to improve the productivity, disease resistance, and processing quality of Chinese wheats. It has also developed human resources and helped build research infrastructure.

“The progress China has made in this period has been impressive in the areas of molecular biology, breeding, and food processing,” says Peña, who thought the conference covered a good balance of topics, ranging from genetics to consumer preferences. “The government is really supporting the research. They have new buildings and modern equipment for molecular biology and wheat quality testing.”

The Quality and Training Complex sponsored by the Chinese Academy of Agricultural Sciences and CIMMYT is a new effort. It offers a testing system for various wheat-based foods, facilities for genetic studies and other research using molecular markers, and training for graduates, postdoctoral fellows, and visiting scientists.

Along with improved wheat and better cropping practices that help farmers save money on costly inputs, such as water, Iwanaga believes that more marketable maize and wheat grain will be important for improving the profitability of maize and wheat production in developing countries. He would like to increase the benefits that farmers reap from their harvests by bettering a range of traits, including taste, texture, safety, and nutrition with added protein or vitamins. That way, farmers can earn more money from better quality wheat.

Conference presentations covered a wide range of topics: molecular studies of the evolution of the wheat genome; new tools to assess heat tolerance and grain quality in wheat genotypes; molecular genetic modification of wheat flour quality; the biochemical and molecular genetic study of glutenin proteins in bread wheat and related species; the molecular investigation of storage product accumulation in wheat endosperm; molecular and conventional methods for assessing the processing quality of Chinese wheat; challenges for breeding high-quality wheat with high yield potential; the impact of genetic resources on breeding for breadmaking quality in common wheat; wheat quality improvement by genetic manipulation and biosafety assessment of transgenic wheat lines; and quality characteristics of transgenic wheat lines.

The conference was organized by the Chinese Academy of Agricultural Sciences / National Wheat Improvement Center, the Chinese Academy of Science, CIMMYT, BRI Australia, Limagrain, and the Crop Science Society of China. It was sponsored by the Ministry of Science and Technology, the Ministry of Agriculture, the National Nature Science Foundation of China, the Grains Research and Development Corporation, and Japan International Cooperation Agency.

For information: Zonghu He

Conservation by the numbers: Reducing genetic drift in crop gene bank collections

Written by on May 14, 2012. Posted in Features.

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

conserving1 CIMMYT’s biometrics team receives special recognition for advancing the science behind crop genetic resource conservation.

The nightmare of a gene bank curator: You have a collection of 25,000 precious, unique samples of maize seed; one of the world’s most extensive. You store it carefully, keep it cold and dry, but—little by little over the years—the seed dies! Eventually you’re left with so many packets of useless kernels, and the precious genetic diversity they once embodied is lost to humanity forever.

To keep this very bad dream from becoming a reality, Suketoshi Taba, head of maize genetic resources at CIMMYT, and his team constantly monitor the germination capacity of collections. When it drops below 80-85%, they take viable seed from the endangered accession (the term for individual, registered samples in the bank), sow it under controlled conditions, and harvest enough from progeny to replenish the accession. Known as “regeneration,” the process sounds simple, but in fact must be done painstakingly to capture a faithful snapshot—rather than a faded copy—of the genetic diversity from the original accession.

The Crop Science Society of America recently bestowed the honor of “2004 Outstanding Paper on Plant Genetic Resources” on an article by CIMMYT biometricians that provides models for proper handling of repeated cycles of regeneration. Their work, which was funded by the Australian Grains Research and Development Corporation (GRDC), is particularly relevant for outcrossing, genetically diverse crops like maize, legumes, or sorghum, to name just a few.

conservation2

“For maize regeneration, we use artificial pollination, to avoid out-crossing with pollen from other maize fields,” says Taba. “But even the individuals in a maize population or accession are genetically diverse. How can we decide on the best way to pollinate the plants, or how many ears we need to harvest, or how many and which seeds to choose from each ear?” According to Taba, the danger is ending up with a sample that differs from the genetic make-up of the original. And with each successive cycle of regeneration, you can drift further and further.

Building on a strong body of work in this area by CIMMYT biometricians since the 1980s, the award-winning paper refines and expands the statistical model and provides reliable computer simulations. “Among other things, the simulation model shows exactly how many alleles are likely to be lost through various sampling and regeneration strategies,” says Jiankang Wang, CIMMYT biometrician who is first author of the study. “It describes how different strategies can affect the conservation of alleles and gives gene bank curators options that can be tailored for specific types of accessions.”

Jiankang Wang says he and his co-author, CIMMYT biometrician José Crossa, are now working with Taba to apply the paper’s model in managing CIMMYT’s maize gene bank collection. “Many other gene banks will find this approach useful,” says Crossa, explaining why their study received the award. “For example, we collaborate closely with the National Center for Genetic Resources Preservation in Fort Collins, Colorado, in the USA. They can apply the same principles in their regeneration work.”

Jiankang Wang was excited by the recognition and the fact that peers might find his work useful. “In middle school, teachers saw I had talent and told me to specialize in mathematics, but at the university I discovered that I was most interested in the practical applications of mathematics,” says Jiankang Wang. “Using science to help preserve the world’s crop genetic resources is a great satisfaction.”

For more information contact Jiankang Wang ( j.k.wang@cgiar.org)

Leaf Rust Resistance Breeding Reaps Great Benefits

Written by on May 14, 2012. Posted in Features.

August, 2004

leaf Every 1990-term US dollar invested in CIMMYT’s wheat genetic improvement over the past 40 years has generated at least 27 times its value in benefits from leaf rust resistance breeding in spring bread wheat alone, according to a recent CIMMYT study entitled “The Economic Impact in Developing Countries of Leaf Rust Resistance Breeding in CIMMYT–Related Spring Bread Wheat.”

Spring bread wheat covers about two-thirds of the developing world’s wheat area, and almost 80% of that area was sown to CIMMYT-related semidwarf varieties in 1997. Using the data on the composition of varieties sown that year, the study estimated the economic impact of CIMMYT’s efforts to develop leaf rust resistant spring bread wheat varieties since 1973.

Puccinia triticina is currently the most widespread rust in the world. The development of durable genetic resistance to this rust has been a plant breeding objective since the early 1900s and a priority of CIMMYT’s wheat breeding program since its inception. Although gene manipulation has brought about more stable patterns of resistance, rust still causes yield losses in many wheat-producing areas.

The rust pathogen can mutate into new races and then infect previously resistant varieties. Researchers cannot estimate productivity maintenance by yield gains, as they do with productivity improvement. Instead, they must estimate the yield losses that would have occurred without the resistant varieties and research investment.

C.N. Marasas, working at the Agricultural Research Council in South Africa at the time of the study, and M. Smale from the International Plant Genetic Resources Institute and the International Food Policy Research Institute conducted the research along with CIMMYT wheat geneticist and pathologist R.P. Singh.

They applied an economic surplus approach adjusted for maintenance research and a capital investment analysis to estimate the returns on CIMMYT’s investment in wheat genetic improvement. The results suggest an internal rate of return of 41%. Allowing for discount factors, the net present value was US$ 5.36 billion (in 1990 dollars), and the benefit-cost ratio was 27:1.

The study emphasizes the importance of maintenance research in crop breeding programs. CIMMYT’s work in leaf rust resistance has made substantial economic impacts in developing countries, where farmers use mainly resistant varieties, not fungicide, to control leaf rust. Findings show that wheat yield increases over the years have been due in part to yield potential protection through disease resistance breeding.

For more information: Dr. Ravi Singh

Solving the Zinc Problem from Field to Food

Written by on May 14, 2012. Posted in Features.

January, 2005

Thanks to pioneering research in Turkey, the links between zinc-deficient soils, plants, people, and continued malnutrition and poverty have been clearly articulated. Few other countries in the world are as well placed to show how plant breeding research can limit the impact of zinc deficiency on crop and human health. So what’s the next step?

In her work as a medical doctor and nutritionist, Prof. Ayhan Çavdar saw many women who could not give birth to healthy children. They had repeated miscarriages and stillbirths. Their babies had agonizing defects of the central nervous system, such as spina bifida, in which the spine fails to close properly, and anencephaly, characterized by an undeveloped brain and incomplete skull. One 18-year-old woman had already miscarried two anencephalitic fetuses. This devastating condition had a surprisingly simple treatment. Çavdar measured the levels of zinc in the young woman’s blood serum, plasma, and hair. They were extremely low. She prescribed zinc supplements for five months. The young woman conceived and gave birth to a healthy child after an uneventful pregnancy.

Zinc deficiency is implicated in health problems throughout the world (see box). The causes and consequences of the problem have been particularly well studied in Turkey, where Çavdar says “a nutrition-related, zinc-deficient milieu exists.”

Wheat is part of that milieu. Most people in Turkey and neighboring countries rely heavily on wheat as a staple. In rural areas, people can consume more than 500 grams of bread every day. Throughout West Asia and North Africa, wheat can constitute from 40 to 60% of daily caloric intake, compared with 21% in Europe or 20% worldwide. People risk zinc deficiency when they subsist on white bread, white rice, or other cereals and consume few vegetables, red meat, or other animal protein.

The Missing Zinc

The widespread zinc deficiency in Turkey’s soils and crops, including wheat, is considered a major
reason for the relatively high incidence of zinc deficiency in its people. In the early 1990s, researchers started a NATOsponsored project in Central Anatolia, Turkey’s major wheat growing area, to investigate the extent and significance of zinc deficiency in soils, plants, foods, and people. Partners included Çukorova University in Adana, the Transitional Zone Agricultural Research Institute in Eskisehir, the Bahri Dagdas International Agricultural Research Center in Konya, the Research Institute of Rural Affairs in Sanliurfa, CIMMYT and Advanced Research Institutes in Australia, Germany, and the USA.

The project, led by Prof. Ismail Çakmak (then with Çukurova University, now with Sabanci University), built on the work of Dr. Robin Graham from Adelaide University in Australia and Mufit Kalayci from the Transitional Zone Agricultural Research Institute in Eskisehir, who had shown the effects of zinc on plant growth and yield. Some wheat varieties, especially those developed from local landraces, used zinc much more effectively than others. Zinc application increased wheat yields by 5-500%, depending on location and soil zinc levels. Also seed that had higher zinc content yielded better than seed with low content.

Çakmak recalls that “when farmers saw the results with zinc fertilizer, they said, ‘Something good like aspirin has come!’ ”Because of the impressive project’s findings, fertilizer companies started producing zinc fertilizer. “Today, ten years after the problem was solidly diagnosed, Turkey uses 300,000 tons of zinc fertilizer. This is a success story,” emphasizes Çakmak. The Ministry of Agriculture estimates that the economic benefit from zinc fertilization in Turkey is about USD 150 million per year.

No Happy Ending—Yet

Plants that get a high dose of zinc fertilizer do not necessarily accumulate enough zinc in the grain to improve human nutrition. Some varieties cannot draw much zinc from the soil. Others easily extract zinc from the soil but cannot make good use of it. Finally, not every farmer can afford zinc fertilizer, and not every country provides it.

“Wheat varieties and landraces, and wheat’s wild relatives, have the genes to solve the zinc problem,” says Hans-Joachim Braun, director of CIMMYT’s Rainfed Wheat Systems Program and participant in the NATO project.

Getting Good Genes

Turkish wheat landraces and cultivars that use zinc efficiently are being combined with wheat varieties developed in the Turkey- CIMMYT-ICARDA International Wheat Improvement Program (IWWIP) that have resistance to yellow rust and root diseases. “We’re evaluating about 180 wheat lines with these traits right now,” says Çakmak. “They’re showing very high levels of zinc efficiency when grown in zinc-deficient soils.” Çakmak and colleagues also found that wild relatives of wheat (Triticum monococcum, T. diccocoides, and Aegilops tauschii) tolerate zinc-deficient soils well compared to bread wheat. “Many of the wild wheats and Aegilops species that exhibit very high tolerance to zinc-deficient soils originated in Turkey,” says Çakmak, “very probably because Turkey has such zincdeficient soils.” They feel this valuable trait can easily be passed to improved bread wheats. Researchers also have high hopes that rye can contribute a similar genetic advantage to wheat.

With funding from DANIDA, CIMMYT evaluated accessions from its wheat genebank for cultivars that produced zinc-rich grain, and considerable variation was found. Çakmak and his team, together with collaborators from Çukurova University (Hakan Ozkan),Tel Aviv University (Eitan Millet), and Haifa University (Eviatar Nevo), have identified wild and primitive wheats from the Fertile Crescent that have grain with seven times as much zinc as modern wheat varieties. Preliminary results also suggest that the grain of wild species has higher levels of proteins and amino acids that make it easier for people to absorb micronutrients such as zinc.

“We have access to nearly 10,000 unique accessions of wild relatives from the Fertile Crescent,” observes Çakmak. “Other research groups are not working with these materials. Because Turkey has zinc deficiency not only in soils and plants but also in people, we’re ideally suited to screen a range of crops for the HarvestPlus program.” (See box below)

HarvestPlus for a More Nutritious Harvest

Zinc deficiencies have serious consequences for health. Because there is no widely accepted method for measuring zinc deficiency, no firm estimates are available on the number of people who are zinc deficient. But billions are at risk for zinc deficiency, with the prevalence highest for South and Southeast Asia and Africa. Zinc supplementation has been shown to reduce by a third the effects of common childhood infections, especially diarrhea, pneumonia, and possibly malaria. In addition, zinc deficiency is an important cause of stunting.

harvestplus2 As part of its contribution to HarvestPlus, the CGIAR’s global alliance to breed and disseminate crops for better nutrition, CIMMYT is developing nutritionally enhanced wheat varieties that will automatically increase people’s intake of essential dietary elements like zinc. Given that CIMMYTderived spring bread wheat varieties are planted on 80% of the global spring wheat area, the impacts could be wide-ranging.

The white bars in the figure above show the zinc content of wheat lines that are far along in the breeding process, of excellent agronomic type, and into which CIMMYT breeders have incorporated high levels of zinc (172% of check, in the best line). The best will be used to transfer this trait to other wheat varieties and for studies in which DNA markers will help researchers identify genes associated with high zinc content.

For more information: h.j.braun@cgiar.org

Truman State University Students See Science in Action at CIMMYT

Written by on May 14, 2012. Posted in News.

September, 2004

truman_students Five undergraduate biology students from Truman State University in Kirksville, Missouri, visited CIMMYT headquarters for four days in August to learn about CIMMYT’s research and observe scientists working in an international environment.

“What they are doing at CIMMYT is on the cutting edge in the molecular aspects, as well as in the traditional breeding programs,” says student Benjamin Schmidt. “Everyone we met was friendly and helpful in explaining the centers’ goals and how they hope to accomplish them.”

Scientists in the Applied Biotechnology Center gave presentations to the students about their research and also provided constructive criticism and new perspectives on the research presentations given by the students. “The best part was the scientists’ willingness to hear about our research and share their research with us,” says student Christopher Spencer.

Their research project, entitled “High-Density Genetic Map of Maize Transcripts,” focuses on comparing the genetic map of thousands of sequenced maize genes to the completely sequenced rice genome. The National Science Foundation grant that funds the project is aimed partly at exposing students to the international scientific community and the challenges faced by scientists who genetically improve plants for the developing world.

Dr. Brent Buckner, the students’ biology professor, thinks the trip’s highlight was a visit to CIMMYT’s subtropical field station in Tlaltizapán. “It was at this point that the students truly came to understand the marriage between laboratory science, plant breeding, and developing maize and wheat to combat world hunger,” says Buckner, who directs their research project.

“It was exciting to see firsthand the field projects that supported and complemented the laboratory projects that had been described to us on the first day, and to which the students had contributed during their shadowing experience,” says Buckner. “CIMMYT was an outstanding place to expose students to how classical breeding methods and molecular genetic techniques are being used together to improve agriculturally important crops.”

After visiting the experiment station, the students met with a local farmer who shared his methods for growing hybrid maize for his family’s consumption. “Seeing a Mexican farmer utilizing the science in the field drove home what the research is all about,” says student Ryan Douglas.

The students toured the Plant Genetic Resources Center, CIMMYT’s germplasm bank, learned about the domestication of wheat and genetic diversity of maize, and shadowed technicians in biotechnology laboratories. They saw the importance of maize in Mexico’s history and culture when they visited the Pyramids of Teotihuacan and the National Museum of Anthropology in Mexico City. The trips emphasized the link between maize cultivation and human development in Mexico, and the role grains have played in civilization.

“This is exactly what I was hoping for from this trip—the chance to interact with the people who make everything happen,” says student Kristen Haley. “I think the experience overall gave us a better understanding of the processes and a broader view of the project’s impact.”

Information for this article was provided by Kendra Knoll, a senior in communications science at Truman State University.

Big Bang from World Wheat Breeding Bucks

Written by on May 14, 2012. Posted in News.

CIMMYT E-News, vol 3 no. 5, May 2006

may01 Global, collaborative wheat research brings enormous gains for developing country farmers, particularly in more marginal environments, according to an article in the Centenary Review of the Journal of Agricultural Science.

Forty years of worldwide, publicly-funded collaborative research to improve the yield potential and stress tolerance of wheat, along with efforts to extend the outputs of this science in developing countries, has lowered food costs for the poor, allowed food supplies to meet the demands of rising populations, brought harvest surpluses worth US$ 3-6 billion each year to farmers, and saved 1.8 billion hectares of natural ecosystems from conversion to farmland, to name a few results.

These and other findings appear in a recent review article by CIMMYT wheat physiologist Matthew Reynolds and 1970 Nobel Peace Laureate Norman E. Borlaug—one of a series of papers to celebrate 100 years of publishing by the Journal of Agricultural Science. The review traces how international wheat breeding over the last five decades has evolved into “…a global agricultural strategic and trouble-shooting network that plays a central role in providing food security in the developing world.” Led initially by CIMMYT and later with the partnership of the International Centre for Agricultural Research in the Dry Areas (ICARDA), the network for wheat and related crops provides a forum “…whereby institutional linkages are fostered and maintained globally, not only through exchange of germplasm, but also through knowledge sharing, training programmes, international visits and development of extended partnerships…” According to the article, centers like CIMMYT and ICARDA have also played a key role in collecting and conserving the landraces and other genetic resources that improved varieties have replaced, making those resources available worldwide and, more recently, ensuring that useful diversity is rechanneled into improved cultivars.

“Given its importance and accomplishments, it’s somewhat surprising that global wheat breeding struggles to find investors,” says Reynolds. Also noted by Reynolds and Borlaug was the fact that most of the increased area of adoption of improved wheat varieties since 1977 has occurred in more marginal, rainfed areas, rather than favored irrigated farmlands, and that yield increases from these varieties during 1979-95 were greater in semi-arid and heat-stressed environments (2-3% per year) than in irrigated areas (just over 1% per year).

“Considering the issue of food security and its positive influence on the livelihoods of poor people, it’s clear that publicly-funded international centers provide a continuity in agricultural development that would otherwise be lacking for many countries where economic, political, and social instability are commonplace,” the authors say.

A companion Centenary Review by Reynolds and Borlaug discusses the future of collaborative wheat improvement, in which, according to Reynolds, researchers will apply technology-assisted methodologies and powerful information tools to identify and breed value-added traits into wheat varieties. “At the same time, however, we’ll continue to seek farmer input to increase the amount of useful genetic diversity in the field and the local adaptation of varieties, as well as in testing and promoting conservation agriculture practices.”

Regarding the future, the authors say: “Policy-makers need to balance the appeal of high-risk investments in the latest technologies with the realities of resource-poor farmers, for whom tried and tested technologies offer immediate and reliable solutions.”

To access abstracts or full-text versions of the articles:

Impacts of breeding on international collaborative wheat research

Applying innovations and new technologies for international collaborative wheat improvement

For more information contact Mathew Reynolds (m.reynolds@cgiar.org).

Maintaining the Genetic Integrity of CIMMYT Seed Collections: New Maize and Wheat Gene Bank Operations Manual

Written by on May 14, 2012. Posted in News.

October, 2004

In 2004, CIMMYT restructured its research programs into six new global and ecoregional programs. One of these, the Genetic Resources Program, is now home to CIMMYT’s maize and wheat germplasm banks. This new organizational structure indicates the high importance and visibility that CIMMYT places on our role as custodians of maize, wheat, and related species genetic resources.

One of the first priorities of the program was to update the operations manual for the germplasm banks. The result of this effort is this publication, the Wellhausen-Anderson Genetic Resources Center Operations Manual. The policies and procedures outlined in the manual represent those currently being used in the introduction, evaluation, maintenance, regeneration, and distribution of genetic resources at CIMMYT. By following these procedures, CIMMYT ensures that the genetic resources entrusted to it in its germplasm banks are available to the world and that they maintain their genetic integrity while under CIMMYT’s custodianship.

Click here to see the manual.

Click here to see CIMMYT’s guiding principles for developing and deploying genetically engineered maize and wheat varieties.

Click here to see CGIAR draft guidelines for GMO detection in gene banks.

Safe in the Bank?

Written by on May 14, 2012. Posted in News.

CIMMYT E-News, vol 3 no. 5, May 2006

may04 Keepers of worldwide maize germplasm collections meet at CIMMYT to see how they can work together to protect and conserve these resources.

Farmers know you protect and save your seed corn (maize) to ensure the next harvest. It’s a lesson the world apparently has not learned as gene banks, which could host tomorrow’s harvest of research breakthroughs and unique traits, find themselves nearly as endangered as the maize varieties and wild relatives they seek to conserve.

The meeting of the Maize Germplasm Network, sponsored by the Global Crop Diversity Trust, the World Bank, and CIMMYT, was called to initiate a global response to this growing crisis. Experts from around the world met at CIMMYT in Mexico in early May to begin hammering out a strategy for the long-term conservation of maize genetic diversity. Neither national nor international maize collections have fared well of late, as investments in public sector agricultural research have steadily declined and fierce competition for dwindling resources in the agricultural sciences has risen.

“People recognize that these collections have unique materials and are valuable,” says meeting co-organizer Major Goodman of North Carolina State University, “but donors simply do not like to get involved with a commitment that lasts forever, and that is what we are talking about with crop genetic resources collections.”

Ironically, the reluctance to invest in these operations comes at a time when molecular genetics opens new opportunities daily to exploit genetic resources carrying resistance to plant diseases, insect pests, and threats such as drought, soil salinity, and heat stress. Collecting and preserving the basic sources of resistance traits takes on added importance.

may05

Meeting participants found “remarkable agreement” on top priorities, says Suketoshi Taba, head of the CIMMYT maize gene bank and co-organizer of the meeting. At the top of the list, he says, is rescuing landraces and adapted germplasm identified as being endangered—both of maize and its wild relative, teosinte. Also urgent is the need to create proper documentation for all collections, both from the Americas (considered “primary” diversity, being from the crop’s center of origin) and from other continents (known as “secondary” diversity). The ultimate aim is to facilitate use of the collections while reducing redundancies and their costs. Once proper documentation is achieved, it was proposed that partners would work to establish a “meta-database” of existing maize genetic databases. The essential but perpetually under-funded activities of seed regeneration and recollection must also be considered. Finally, participants agreed that CIMMYT should serve as the coordinating institution for advancing the identified priorities forward on the international scientific agenda.

The meeting co-organizers expressed the consensus of the group in stating that the challenges they face are beyond the capacity of any single institution or nation—thus the need for a broad-based solution. They also observed that clearly there are roles, such as the costly long-term maintenance of collections and distribution of seed for research, that are better assumed by large gene banks, such as those at CIMMYT or the USDA maize collection at Ames, Iowa. These banks, however, find it difficult to regenerate varieties that originated in tropical or highland areas, a role better played by national gene banks. Furthermore, the national banks, when properly resourced, can more efficiently collect new seed and distribute seed from collections to local plant breeders and biologists. But those wishing to implement such a division of tasks must first overcome barriers of plant ownership rights, nationalism, phytosanitary regulations, and a tower of database babble that hampers effective documentation and use of collections.

“I am sure that there is a role for the Trust in this work, particularly in securing unique materials, securing landraces, and helping with the backlog of materials that urgently need regeneration,” says Brigitte Laliberté of the Global Crop Diversity Trust. “But it is critical to the Trust that a global system and strategy is established whereby there are roles for international organizations and good links with national programs. This meeting was a constructive first step.”

For more information contact Suketoshi Taba (s.taba@cgiar.org)

Ravi Singh receives prestigious prize

Written by on May 14, 2012. Posted in News.

The University of Minnesota recently announced CIMMYT distinguished scientist Ravi Singh as the recipient of its 2010 E.C. Stakman Award. Established in 1955 by plant pathologist E.C. Stakman, a pioneer in combating wheat diseases, the award is given to individuals for outstanding achievements in plant pathology. Stakman was also a former professor of Norman Borlaug.

“I feel extremely honored and humbled to receive this highly prestigious award,” Singh said. “Dr. Stakman was a mentor to Dr. Borlaug and is largely responsible for sending him to Mexico in 1944. You wonder whether Dr. Stakman knew or even guessed that this decision was going to change history and save millions of lives.”

Singh, who has been with CIMMYT for over 25 years, is world-renowned for his efforts to control wheat rusts and has trained over 400 young scientists. With this award he joins a long list of notable scientists, including I. A. Watson, who was dean of Sydney University’s College of Agriculture and a former pupil of Stakman himself, and 2007’s recipient, the late Bent Skovmand, former head of wheat genetic resources at CIMMYT, director of the Nordic Gene Bank, and key player in the development of Svalbard International Seed Bank.

Congratulations, Ravi!