SATrends Issue 18 

May 2002

NEWS FROM THE DRY TROPICS:

1. Gerrymandering the Gene Pool

Part 1: In the beginning . . .

Growing a food grain crop, from sowing to harvest, takes anywhere from 2½ to 4 months. Considering that time is required for field preparation, and that not all crops will grow each season, it is reasonable to assume that not more than two crops can be cultivated in a given year.

genetics copy.jpg (10055 bytes)We know that characteristics of living things are derived from the genes bequeathed by both parents. Scientists have engineered the reproductive process to produce hybrids, which carry selected traits of both parents. The first generation of such an engineered cross is called the F1 generation, and this generation is genetically uniform. When the parents of the F1 hybrid have been chosen correctly, the hybrid will show ‘hybrid vigor’, or heterosis. Hybrid vigor means that the characteristics of the F1, such as high yield or pest resistance, are superior to those found in the parents.

Subsequent cross breeding produces generations F2, F3, and so on, provided that at least one parent is from the previous generation (F1 is a parent of F2, and F2 is a parent of F3, and so on).  Left, top is a graphic description of an F1 expression, bottom row, F2 , leftmost graphic shows expression of all the good genes.

Thus, to determine that a certain characteristic be expressed in the crop, several selective crosses and re-crosses must be grown, a process that takes several years of conventional cross breeding to achieve. This approach amounts to working in the dark, since the scientist doesn’t know what genes are present or absent in a plant before using it for breeding.

Genetic markers, which became popular the 1970s, are used to combine, for example, many resistance genes in a single plant, thus making resistance more effective and stable. The technique is called marker assisted breeding. This process helps the scientist select plants not through field screening, where the physical characters indicate a possible gene (a process called phenotyping), but through gene screening (genotyping), where the presence of a gene is most probable. Since marker assisted breeding speeds up the breeding process, it is sometimes known as marker accelerated breeding.

Three stages lead to success with marker assisted breeding:
  1. marker development,
  2. genetic linkage maps and mapping genes contributing to traits of interest, and
  3. the actual assisted breeding process.
Details about each of these stages will be made available in forthcoming issues of SATrends.

For more information contact j.h.crouch@cgiar.org

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2.Snap, Crackle, and Pop

Everyone loves popcorn – except sorghum breeders. Why pop corn? they ask. Why not pop something else? Sorghum, for example.

popsorghum-1 copy.jpg (10061 bytes)Some of maize and sorghum, when exposed to heated cooking oil, pop when their grains expand to many times their original volume. Only a few maize varieties – but almost all sorghum varieties – can be popped. ICRISAT sorghum breeders have improved popping quality (quicker and more even expansion) through careful selection, and have developed a range of good pop sorghum varieties, suited to different environments.

Professor Babatunde Obilana, an ICRISAT sorghum breeder based in Nairobi, is the driving force behind these efforts. Not content with developing the varieties, he conducts demonstrations at every opportunity to show people that pop sorghum tastes every bit as good as popcorn. A recent demonstration to professional catering staff at the World Agroforestry Centre in Nairobi was a case in point. They were completely bowled over.

popsorghum-2 copy.jpg (9803 bytes)There were comments like ‘My grandmother used to make something similar, but I haven’t had it for many years… This is much healthier than the popcorn we buy at silly prices…’ as well as lots of technical questions about making pop sorghum in bulk.

Two varieties were demonstrated: Macia (white grain) and KARI Mtama 3 (red grain). The audience sampled the results, both salted and unsalted. Conclusion: Macia tasted better, but the best “presentation”, as caterers call it, was a mixture of the two varieties, with their contrasting colors.

And it’s so easy, even a breeder can do it! popsorghum-3 copy.jpg (9269 bytes)
  1. 1. Place 5 ml of cooking oil in a covered pot, heat until smoking hot.
  2. 2. Add 50 g of sorghum, heat on a low flame, shake periodically so that sorghum grains are heated evenly, not scorched. Wait until all the grains have popped. This will take only a few minutes.
  3. 3. Sprinkle salt to taste.
  4. 4. Enjoy.
But why do scientists bother with this unconventional product? The answer – to promote sorghum commercialization. Sorghum farmers everywhere have one major problem – lack of demand. Prof Obilana is trying to promote utilization in various forms – ready-made sorghum porridge mixes, sorghum-based malt for breweries, sorghum-wheat composite flour for bakeries, and now pop sorghum. Popcorn has not penetrated rural Africa, or even most towns on the continent. But sorghum is available at home, and if rural consumers can be persuaded to try this easy-to-prepare snack food, consumption will increase. More consumption means more demand, and more incentives for sorghum farmers to increase production.

For more information contact a.obilana@cgiar.org

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3. Checking Africa's Pulse

Although pulse crops like chickpea are indigenous to Asia, they have been grown in various places in eastern Africa for many generations. Nowhere in Africa are legumes more in favor with farmers than in Ethiopia, where a total of 1.24 million hectares were sown to legumes in 2001. This is not surprising, since that country lies at the geographic and cultural crossroads of the two continents.

Today, Ethiopia produces over 50% of all chickpea grown in Africa. Cultivation is increasing steadily:

  • 170,000 hectares in 1999
  • 190,000 hectares in 2000
  • 212,000 hectares in 2001
Man with chickpea copy.jpg (10335 bytes)Ethiopia exports chickpea to several countries including Pakistan, India and Dubai. Demand outstrips supply. Recently, for example, a group of Israeli businessmen were so impressed by the high quality of Ethiopian chickpea that they requested 6000 tons. The amount was far more than could be supplied, but farmers are well aware of the thriving international market for chickpeas.

Dr Geletu Bejiga, Director of Crop Research of the Ethiopian Agricultural Research Organization (EARO), an old hand with chickpea who has collaborated with ICRISAT and ICARDA chickpea scientists for many years, tells an interesting story that illustrates the increasing importance of the crop. While visiting the local market at Debre Zeit, the location of Ethiopia’s oldest agricultural research station, a farmer told him that he now grows chickpea in preference to coffee because he finds it more lucrative.

According to Dr Seid Ahmed, Director of the Debre Zeit Agricultural Research Center and Senior Pulse Pathologist, ICRISAT-derived varieties have been of enormous importance in EARO’s pulse breeding program. One desi variety that has found favor with farmers is Mariye (‘honey’, so named for its sweet taste as well as its color). A popular kabuli variety is ICCV 93512, popularly known as Shoshu, which means ‘white’.

Growing conditions vary tremendously in Ethiopia, and EARO scientists must pay careful attention to variations in altitude. Another concern is choice of growing season: Ethiopia has two cropping seasons, meher (the long rains) and belg (short rains). Finding the appropriate mix for each variety is a complex challenge.

What of the future? Dr Bejiga wants to set up a network to link research on legumes in the region into an international network. In view of Ethiopia’s comparative advantage, he suggests that the network coordinator be based at Addis Ababa.

In Ethiopia, chickpea is not a ‘crop of the future’. It has come to stay.

For more information contact s.silim@cgiar.org or GeletuB@yahoo.com

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4. High Tech for an Old Problem

Drought is possibly the most complex and least understood of natural hazards. The effects of drought accumulate slowly and linger for years. It is estimated that 380 million people, 38% of the world’s rural poor, live in the arid and semi-arid tropics. Of those who are vulnerable to drought, more than 90% are either smallholder farmers or landless laborers.

Information is essential for drought preparedness and management. Information and communication technologies (ICTs) can play an important role in combating the effects of drought in remote regions. Contemporary ICTs can rapidly collect and disseminate data to predict climate changes by analyzing meteorological and hydrological information. Early warning systems can then advise farmers on appropriate action.

Village-level ICTs can reduce the time lag between research to adoption and farmers have access to crop cultivation and livestock management options. ICRISAT’s 30 years of agricultural research in the dry tropics make it an ideal information provider on drought. Our knowledge base can be developed with global coverage and an emphasis on sub-Saharan Africa and South Asia.

Drought webpage copy.jpg (9272 bytes)The ICRISAT-pioneered knowledge system, www.droughtweb.org, is the solution. It provides a database of global experts who can interact with each other as well as with those who seek their advice. A collection of research papers on drought management – crops research, natural resource management, livestock, meteorology, socioeconomics, and so on – are also available. The website links to drought mitigation/management projects and networks that take up inputs from research. Another feature is an exclusive link to an annotated database on crops research information. A link to a regional information system will enable users to access forecasts of various regions so they can assess the chances of drought in the coming season.

User needs are an important consideration in this effort. Whether the user is a national organization, an individual researcher, a policymaker or an NGO – all deserve help in formulating their plans for coping with drought. ICRISAT has developed a project to use UNICODE-compatible fonts/typefaces in various languages to ensure that information is disseminated in regional languages.

The combination of knowledge-sharing approaches, connectivity and interactivity will ensure that the portal is able to deliver useful and timely information. Both the NGO-led movement for the establishment of rural telecenters and India’s Ministry of Agriculture are strongly supportive of this effort.

For more information contact v.balaji@cgiar.org

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Highlights of Previous Issues:

April 2002: Disaster Relief with a Difference•From Crop to Tabletop •Golden Millet, Naturally! •The "Green" to "Blue" Water Continuum

March 2002: On the Wild Side •A Handful of Seed •Here's to Fungus - hic!

February 2002: 36 Percent -- and Rising •Of Stalk and Livestock •Stalking the Enemy •Sorghum Scoop from Mali

January 2002: Back to the Drawing Board •Weed Better, Weed Faster •With Minds of their Own! •Closing Ranks against the Pod Borer

December 2001: It's a bird! It's a plane! No, it's a Super scientist! •Viva Sorgo! • Small is Big! •Abortion Leads to Rebirth

November 2001: Sorghum Products: Poised to Take Off •Cash from Cattle Food •Empowerment Through Technology •Outwitting an Unfair Bug

October 2001: Backing a Winner •More than a Thousand Words •Sowing a New Future for Eritrea •A Casting Coup: Farmers' Day 2001

September 2001: Don’t Get Left on the Shelf • Nigeria Targets ‘Groundnut Leprosy’ •Two Heads Are Better than One • Desperately Seeking Seeds

August 2001: Finding Chinks in the Armour •  Brazilian Farmers get a Boost from the Sahel •Sahelian Partners Smash the Ivory Tower •What You See is What You Get - Simulation Modeling for Successful Farming

July 2001: Balaji Makes IT Waves • A Hot Date in the Sahel •It All Adds Up •More from Less •That's the Way the Cookie Crumbles

June 2001: Space-Age Partnership in West Africa • Bad Taste is Good • Out of Africa • Seed Priming: Rhapsody in Simplicity

May 2001: Dodging Drought in Kenya •Vietnam and ICRISAT Save Watersheds •Farmers Enrich Malawi's Soils •Groundnut Mystery Disease Identified

April 2001: Women Farmers Guide Scientists in Namibia •  Ashta Puts it Faith in IPM •Sahelian Farmers Place Their Bets •China and Pigeonpea: Love at Second Sight

March 2001: Agriculture: an Ally Against Global Warming? • Breaking the Spell of Witchweed •Groundnut Taking Root in Central Asia and the Caucasus •Zimbabwean Smallholders Drive the Research Agenda

February 2001: Somalia: Seeds Deliver Hope Amidst Chaos • The CGIAR Fights Desertification in Africa • Creating the World's First Molecular Marker Map of Chickpea •Aflatoxin and Cancer: Cracking a Hard Nut in Developing Countries

January 2001: Things Grow Better with Coke®: Micro-fertilizer System Sparks 50-100 Percent Millet Yield Increases in the Sahel •Groundnut (Peanut) Production Accelerates in Vietnam •  Pigeonpea Broadens Farmer's Options in Sudan •  Private Sector Invests in Public Plant Breeding Research at ICRISAT.

December 2000: International Symposium on SAT Futures •Centers Team Up to Help East Timor •Spatial Variability in Watersheds •World's First Cytoplasmic Male-Sterile Hybrid Pigeonpea •Groundnut (Peanut) Variety Boosts Malawian Agriculture •National Researchers Persevere in El Salvador •ICRISAT Celebrates India-ICRISAT Day •ICRISAT and World Vision International Work Together in Southern Africa.

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