Report on the Pearl Millet
Research Planning Workshop:
Facilitating the improvement of pearl millet in West Africa
through conventional and molecular plant breeding, farmersÕ participation, and
comparative genomics strategies.
Held in Bamako, Mali
October 9-12, 2002
Co-sponsored by:
The
Rockefeller Foundation
ICRISAT
(International Crop Research Institute For the Semi-Arid Tropics)
The
Institute for Genomic Diversity (IGD), Cornell University
Syngenta
Foundation
German Ministry for Economic Cooperation/GTZ
(Agency for Technical Cooperation)
INTSORMIL (Sorghum and Millet International
Research)
DFID Plant
Sciences Research Programme (Department for International Development, UK)
Table of Contents
Participants' contact information
Introduction to MilletGenes database
Opening remarks of ICRISAT-Mali representative
Closing remarks of ICRISAT-Mali representative
Summary Report on the Pearl
Millet Research Planning Workshop:
Facilitating the
improvement of pearl millet in west Africa through conventional and molecular
plant breeding, farmersÕ participation, and comparative genomics strategies.
Held at
Bamako, Mali October 9-12, 2002
Co-organizers: Dr. Eva Weltzien Rattunde, ICRISAT, Bamako, Mali
Dr. Theresa Fulton, IGD, Ithaca, NY, USA
Dr. Rebecca Nelson, IGD, Ithaca, NY, USA
Executive Secretary: Safiatou Ba, ICRISAT, Bamako, Mali
Sponsors: The Rockefeller Foundation
ICRISAT (International Crop Research Institute For the Semi-Arid Tropics)
The Institute for Genomic Diversity (IGD), Cornell University
Syngenta Foundation
German Ministry for Economic Cooperation/GTZ (Agency for Technical Cooperation)
INTSORMIL (Sorghum and Millet International Research)
DFID
Plant Sciences Research Programme (Department for International Development,
UK)
Rationale and objectives:
Pearl millet is an important food crop in West and Central Africa. Farmers living in agriculturally marginal areas depend upon it. While farmersÕ varieties are adapted to highly stressful local conditions, they are often susceptible to pests and diseases, and farmers suffer large and recurrent losses. Few improved cultivars with strong and stable pest and disease resistance are available to farmers. Tremendous genetic diversity is present in West Africa however, and the crop is an excellent candidate for improvements via plant breeding and molecular marker strategies.
In recent years, research investments in this crop and in the region have decreased sharply. We thus convened this workshop to identify ways to maximize both current millet resources and those available for related grasses, as well as to attract donor support for jointly conceived and planned research initiatives. The title of the workshop was: ÒFacilitating the improvement of pearl millet in West Africa through conventional and molecular plant breeding, farmersÕ participation, and comparative genomics strategies.Ó
We pursued three main
objectives:
1. To inform researchers on the current status of millet improvement, including key traits (i.e., resistance to downy mildew, Striga and insect pests; yield components, etc.) and social and agro-ecological issues (farmer participation, population genetics and diversity, farming systems etc.);
2. To discuss comparative genomics in the grasses and how these resources may contribute to millet improvement; and
3. To identify opportunities for new projects and areas in particular need of further research.
The workshop was held at Bamako, Mali in West Africa from 9-12 October 2002, at the Grand Hotel. The workshop language was mainly English, and informal translation into French was available (with occasional reverses).
Agenda and participants:
The program included a one-day field visit to the Malian National research station for Pearl millet research at Cinzana, and to farmersÕ fields in the area. We attempted to maximize interactions and discussions among participants. Each discussion session was preceded by a small number of presentations on issues or research advances that might be of key importance for the future of pearl millet research and development. Participants were chosen to represent a wide diversity of expertise, including farmer representation, plant breeding, molecular biology, comparative genomics, participatory breeding, plant pathology, etc. A list of participants can be found in an upcoming table.
Key updates, discussion
points and general recommendations:
1. Researchers working on pearl millet may benefit from genetic information available from work on related crops (rice, maize, wheat, etc.). There are genomic regions that have similar functions across crops. There are a number resources available for genomics research of millet as well (see List of resources, List of key references, and Introduction to MilletGenes), molecular maps, QTL maps, BAC libraries, etc. There is now a need to move from random diversity to functional diversity, relating function to field. The Challenge Program of the CGIAR may be a good source of information in the near future.
2. Important constraints to millet production include: drought and heat, poor soil fertility and phosphorus uptake, downy mildew, Striga, several insects and other fungal diseases. A general constraint is that it is a ÒminorÓ crop globally, making it hard to build a critical mass of researchers. The end users are mostly very resource-poor, often not aware of new varieties, and cannot afford to buy seed or fertilizers. Farming is mainly subsistence, with little remaining for possible marketing. Networking, extension services, and training are very important.
3. Researchers need to consider the appropriate use of technology for their situation. For example, it many cases it may be a better use of resources to have an outside source handle DNA sequencing, rather than each lab buying expensive equipment that is difficult to maintain and quickly obsolete. Although some felt it important for each lab to be up to speed on all new technology, equipment and techniques, most felt this would often be an inefficient use of resources. Team building, collaboration within countries and across the region was advised to achieve a wise use of available resources..
4. Farmer participation in plant breeding helps to ensure that new varieties are well-adapted and acceptable. New varieties must be tested in the environments in which they will be used. As research stations are few this can only be achieved by collaboration with farmers. The National farmers organization (AOPP) is developing new relationships between farmers and research organizations in this respect.. Photoperiod sensitivity is key for adaptation to specific zones, and needs to be considered as a key trait for new varieties.
5. The diversity of millet is very complex and to date the structure of its diversity is poorly understood. Wild and weedy forms are often present in the fields and are harvested for food by women. Farmers select and keep their own seed for sowing the next year. Cases where farmers mix seed of different varieties have also been reported. These can be complicating factors for the introduction and use of improved varieties. Thus cultural and agricultural practices must be considered in designing strategies for varietal development.
6. Whether West African farmers would benefit from the use of hybrids was hotly debated. Single cross hybrids are now the most widely grown millet type in India. Advantages include higher grain yield, earlier maturity, and the biologically built in varietal protection favoring private sector breeding investments in research. However, at this time there is no private seed sector in West Africa, no availability of credit to farmers, and hybrids can be more vulnerable to diseases due to their genetic uniformity. There may be more opportunity for hybrid use in the future, particularly in Nigeria which has an emerging private seed industry interested in dryland cereals, and is about to have its first commercial hybrid release. A pilot study assessing heterosis and hybrid superiority over varieties commonly grown by farmers is urgently required. This should be done across the key production zones in WCA.
7. Marker assisted selection (MAS) can be an important tool in assisting conventional and participatory breeding in West Africa. DFID alone has spent approximately $5 million on molecular marker research in pearl millet. There is now a detailed molecular map with many types of markers, including many QTLs for a range of traits, and comparative maps available. There is a need for increased numbers of markers, QTL identification, and sequencing of important regions, The slow incorporation of the use of these tools (possibly due to a downturn in agricultural funding) has been disappointing. It was noted that an outcrossing crop such as millet does pose additional challenges in using markers. Most felt that the benefits (speed in selection, ease in screening over field testing) outweighed these constraints, especially as there are now new options for using the markers for non-inbred parental materials. But in the region expertise for application of these tools is scarce.
8. Backcrossing is one key method for incorporation of known QTLs into new target varieties. Backcrossing of specific QTLs has produced unexpected positive results for several complex agronomic traits. This has been observed recently in millet, and other crops.
9. A new population improvement strategy was presented: the Dynamic multiline population concept. This strategy attempts to develop more durable disease resistance, and allows application to hybrids. It integrates attributes of gene stacking and multiline approaches, and the concept of confronting dynamic and variable pathogens with dynamic and variable host populations. The US had success using this approach against rust.
10. Downy mildew resistance is still a top priority, both in India and Africa. 65 QTLs for resistance have been mapped, but as the pathogen is highly variable, stability of any resistance must be continually monitored. Marker assisted selection would be greatly helpful for effectively using these QTLs.
11. Drought remains a key abiotic factor limiting millet yields, in close interaction with the lack of soil nutrients. Tolerance is difficult to find and evaluate. A QTL on linkage group 2 seems to have good potential. Selection for heat tolerance has been unsuccessful so far, due to the lack of a good screening methodology. Given the difficulty of improving drought tolerance, resources might be better utilized by investing in research on soil fertility, in particular phosphorus uptake, particularly in the Sahelian region (see recommendations for this region).
12. ÔGolden milletÕ varieties, varieties with high beta-carotene levels, have been identified. There is a need to transfer the trait to high yielding, disease resistant lines, and assess. A research proposal is being assembled. There could be a good market opportunity for this as it is a ÔnaturalÕ source (as compared to the transgenic rice varieties).
Recommendations for specific
constraints:
These recommendations were arrived at by dividing the group into 3 smaller working groups of people particularly interested in one of 3 topics: drought and soil fertility; diseases and biotic streses; and insects.
1. Drought and soil fertility:
Three types of drought were identified, based on presentations during the workshop: seedling, mid-season and terminal drought. Although farmers have identified seedling drought as being the most important issue, no good screening procedure is available. A review needs to be done to see what other work has been done on seedling drought tolerance. For mid-season stress, it was decided that there is not much room for improvement. For terminal drought, the QTL on ch2 from Iniadi could be moved in to other farmer preferred varieties, using backcrossing with 2 flanking markers only (at a cost estimate of $20,000). However, since financial resources are an issue, it was recommended to focus on soil fertility rather than drought. Soil fertility is a better short term target. There are management issues which should be integrated into any genetic approach (such as rotation, intercropping). The core collection should be evaluated along with local materials and some wild genotypes. Evaluation would be in the seedling stage, by phenotype, but also on the genetic side, the citrate synthase genes that have been found in maize and rice could be used. Sequences from the database for these genes could be pulled out, primers made, and all accessions screened with these markers for variation and association with drought tolerance.
2. Diseases/biotic:
Downy mildew, Striga, smut, ergot, were cited as the most important, in order of importance, with the first 2 being by far the most important. It was noted that most farmers are aware of the symptoms of DM, but not the source or life-cycle of it. Chemical treatment which is available to prevent DM, by the application of Apron plus (a systemic fungicide) was accepted by farmers, but availability of the product at the right time is often a problem. Thus new varieties with improved stable resistance is a very important goal. Especially for hybrid varieties, specific attention needs to paid to downy mildew resistance, as they are genetically more uniform than open pollinated varieties, and breakdown of resistance can happen very rapidly. For striga, new sources of resistance have only recently been identified in the wild progenitor of pearl millet. It remains to be explored whether and how these resistances can be transferred to farmer acceptable varieties. Research results on other components of integrated Striga management are more advanced, and need to be tested and refined for application to farmers' production conditions. Such research is in progress, and should receive wider support.
3. Insects:
It was decided to consider insects as three types: those on the panicles, on stems and leaves, and in the soil. The group focused on the Sahelian zone. There are available treatments such as insecticides, but it is not known how well they work, and farmers can rarely afford to buy them. Mechanisms of resistance were discussed, such as compactness, grain number per floret , aristation (bristles), length of panicle, grain filling speed. Using conventional methods, rearing the insect in the laboratory for egg production, participatory screening in farmer fields, and especially finding hot spots of infestation for good screening, could be important. Using molecular biology techniques, and evaluating the biochemistry of the chemical secreted that allows the oviposition were also recommended. Mutation breeding by deletion to obtain material that is less attractive to the insects could be attempted. Selection of varieties which produce less chemical is another option. Transformation using the BT gene against millet head miner and stem borers could be an exploratory project.
Recommendations for specific regions:
These recommendations were arrived at by dividing the group into 3 smaller groups. Each group was given a region (the Sahelian zone, the Sudanian zone, or Nigeria) and asked to decide what the key problems of that region are, and develop recommendations to solve this problem(s).
1. In the Sahelian zone, food security , and thus increasing yield, was seen as the top priority. There were varying opinions, however, whether marketing strategies should follow, or whether producing marketable items is in itself a strategy for improving food security. It was noted that technology transfer and possibly changes in marketing would have to accompany any progress to effect real change. However it was pointed out that socio-economic groups are working on this. The group thus proceeded to look at the importance of specific traits. This group considered the ease and difficulties of improving it by selection, the research investment in it so far, and the availability of other crop management options, than varietal change. Five traits were prioritized, results are given in the following table (H = high, M = medium, L = low).
|
Importance |
ease |
investment |
other mgt options |
|
Soil fertility |
H |
VL |
M |
|
Drought |
M |
H |
L |
|
Striga |
M |
H |
M |
|
Head miner |
L |
M |
L |
|
Quality |
M |
H |
L |
Drought is a difficult problem; high investment into this has not yielded good results to date. Therefore it was decided that the best way to address the needs of the Sahelian region is by tackling the problem of soil fertility, in particular phosphorus uptake. Adding phosphorus can increase the ratio of photosynthesis even if rainfall amounts is low. The question of what form of phosphorus to add or what type of phosphorus uptake potential to breed for needs to be addressed; rock phosphorus is in fact available locally, but has been unexploited due to affordability. In response to a question as to why downy mildew did not appear on this list, it was noted that the Sahel is very dry, and mildew is less of a problem. Thus the key recommendation from the group addressing this zone was to invest more research into phosphorus uptake. In response to concerns that a breeding approach to this is not realistic, rather other management practices could be addressed, the group responded that breeding for this is possible, genetic variation has been demonstrated, and that their recommendation was to combine management practices with breeding for varieties that could use local phosphate more efficiently.
2. For the Sudanian zone, the intensification of production was recommended as the most important objective for research in this area. Thus the improvement of grain yield productivity was seen as the most important target. The first constraint was seen as biotic: striga, mildew, and insects; then abiotic such as soil fertility and water use efficiency. Technologies such as seed technology are also a problem. The socio-economic issues here are key, and need to be addressed in any strategy. For improved productivity it was seen as key priority that the varieties are well adapted, key to which is photoperiod sensitivity (due to the unpredictability of the rainfall in the beginning of the season in the region), improved harvest index, and resistance to Striga and other stresses. A participatory approach incorporating the use of marker assisted breeding would be most efficient. Farmer organization and the training of seed producers would facilitate the adoption of new varieties, and also set the region up for possible hybrid production in the future.
3. Nigeria was seen as the region closest to being able to use hybrids, so the recommendation for this region was to stress production-related issues. Seed production and variety maintenance, hybrid breeding and utilization are key items needing attention. Education will be very important, and should include the seed companies, extension and NGO education, incentives and agronomic practices. Since downy mildew, a key problem in this region, tends to break down resistance, continually identifying diverse resistances is important. Marker assisted selection should be used to stack the many known resistance QTLs into new varieties. A specific recommendation was to re-examine the single cross hybrid that is currently in use (anticipating that the resistance will probably break down) and possibly replace this with a population-type hybrid. Regarding Striga, since breeding might now be an option, but very resource intensive , it was decided that marker assisted selection would be the most efficient method of making progress. Specific markers do need to be identified, and protocols need to be defined. Resistance must be crossed into adapted germplasm. In addition, it was recommended that increased attention be paid to grain quality traits and grain utilization. It was noted that it will be increasingly important to identify traits important in grain quality, storage quality and practices, and exploring alternative end uses for the grain (exploring alternative end markets, and export possibilities, poultry and ostrich rations, processed products, etc.).
4. An overarching recommendation was that socio-economic issues must be taken into consideration in all crop improvement programs for any real change: participatory breeding, marketing policies, local preferences, crop management, etc. The breeding of new varieties without taking these things into consideration has been very ineffective.
Results and follow-ups:
1. Proposal is in progress to Rockefeller Foundation on testing heterosis and hybrid superiority (contact Dr. Tom Hash).
2. The McKnight Foundation is planning a followup planning meeting in late 2003, to be followed by a call for proposals. Please contact Dr. Rebecca Nelson with questions.
3. Several concept notes and proposals are now in progress on several fronts: drought tolerance QTL work, phosphorus acquisition and use efficiency, and possibly striga resistance. A PhD research topic was also developed for one of the participants.
Complete notes from the workshop, papers written by the presenters, and some of the powerpoint presentations are available from Dr.Theresa Fulton at tf12@cornell.edu.
Programme for the Pearl Millet Research Planning Workshop
Day 1: Wednesday ,
9 October 2002
Organizers: Dr. Samba Traore, IER, and team
Boreima Traore, CRU Segou,; I. Coulibaly, AOPP
Objectives:
1. Expose participants to and discuss with farmers key constraints faced by pearl millet producers.
2. Show research facilities at Cinzana for pearl millet research, and key products of pearl millet research to date.
8:30 Ð 8:45 Welcome address by Minister of Agriculture
8:30 Ð 8:45 Welcome address by Director of Research/DG of IER
8:45 Ð 9:00 Opening address by ICRISAT Representative
9:15 Ð 9:45 Background, objectives, expectations for the workshop by co-organizers, development investors and key partners
9:45 - 10:15 coffee
break
First session: New tools for resolving specific key constraints of pearl millet
Primary objective: sharing of new insights, i.e. presentations are key. Group discussion topic: For each of the participating WCA countries how and for what would you wish to apply these tools?( As it stands now there is no time for discussion)
10:15 Ð 10:45 Current comparative genomics initiatives in the grasses and implications on millet research (Steve Kresovich)
10:45 Ð 11:00 Pick up from 1997 ÒMarkers in milletÓ conference (Hyderabad): marker updates; milestones reached; constraints and challenges. (John Witcombe)
11:00 Ð 11:15 Resistance to downy mildew of pearl millet (Tom Hash)
11:15 Ð 11:30 Drought tolerance (Harold Roy-Macauley)
11:30 Ð 11:45 Mapping and Marker Assisted Selection (MAS) in drought tolerance. Update of work in heat tolerance (Rattan Yadav)
11:45 Ð 12:00 Downy
mildew variation and disease management (Daniel Gwary)
12:00 Ð 12:15 Use of genetically diverse millet populations for disease management (Jeff Wilson)
12:15 Ð 13:00 Discussion
13:00
Ð14:00 Lunch break
Second session: Opportunities from research on new traits: Research advances in new traits, new light on Òold traitsÓ
Primary objective: sharing of new insights; revisiting old traits with new insights in mind. Discussion topic: What are the key lessons that can be carried over from new traits and new research to improve research on traditional traits or using traditional methods?
14:00 Ð 14:15 Grain quality traits and stover quality: potential for adding value? (Tom Hash)
14:15 Ð 14:30 Photoperiod sensitivity and adaptation: importance for yield improvements (Mamoutou Khouressy)
14:30 Ð 14:45 Tolerance of low fertility/low phosphorus soils (Bill Payne)
14:45 Ð 15:00 Striga resistance (Angarawai Ignatius)
15:00 Ð 15:30 Break
15:30 Ð 17:30 Group
Discussions
Third session: Pearl millet agro-ecologies in West-Africa; farmersÕ preferences and priorities
Primary Objective: Update on farmersÕ preferences
and priorities, key constraints, and regional issues. Discussion topic: How can
the new possibilities and opportunities discussed in Sessions 1 and 2 be
combined to define new research priorities?
08:30 Ð 09:00 Key constraints faced by pearl millet farmers (in the Segou region); by Rep of AOPP, and CRU-Segou (Ibrahim Coulibaby, Boreima Traore)
09:00 Ð 9:30 FarmersÕseed management and preferences (Gilles Besancon)
09:30 Ð 09:45 Millet agro-ecologies and farming systems in W. Africa & their dynamics of change. (based on outcomes from CFC project planning meeting in April 2002), (Samba Traore)
9:45 Ð 10:00 Farmer preferences with regard to pearl millet in W. Africa (Gospel Omanya)
10:00 Ð 10:30 Coffee
Break
10:30 Ð 13:00 Group discussion on identifying key constraints, prioritized for different agro-ecologies
13:00 Ð 14:00 Lunch
Fourth session: Opportunities for integrating application of new research tools with decentralized pearl millet improvement efforts with immediate benefit for users.
14:00 Ð 14:15 Regional Network for Research on Pearl Millet in West and Central Africa (ROCAFREMI): overview, key achievements and outlook (Roger Zangre)
14:15 Ð 14:30 Pearl millet hybrids for Western and Central Africa: prospects and constraints (B. Ouendeba, K.N. Rai and Siaka Boreima)
14:30 Ð 14:45 Population genetics/diversity in relation to key traits Ð considerations for developing a selection strategy (Thomas Presterl)
14:45 Ð 15:00 Integrating seed system innovations into participatory breeding: experiences and outlook (Eva Weltzien)
15:00 Ð 15:15 Break
15:15 Ð 17:30 Group Discussion: Basic concept for pearl millet research strategy in WCA.
Fifth session: Project planning in small groups.
Final Discussion: defining key frontiers, and opportunities for new research; planning joint research project(s)
Closing session.
Pearl Millet planning Workshop
Grand Hotel (Phone: (223)
222 24 81)
Bamako, Mali 09-12
October 2002
Name
|
Title
|
Institute
|
Address
|
|
|
1. |
Adama Traore |
Representant du Ministre du Developpement Rural |
M.D.R |
CNRA,
Bamako Mali |
|
2. |
Amadou Diadie Cisse |
D.G adjoint I.E.R |
IER (Institut de Economie
Rurale), Mali |
Rue Mohamed V, BP.258,
Bamako Tel: (223) 222 26 06 Fax: (223) 222 37 75 Email: diadie.cisse@ier.ml |
|
3. |
Joseph J.Adu-Gyamfi |
Agro-Physiologist and
Country Representative |
ICRISAT |
ICRISAT-Kano, Sabo Bakin
Zuwo Road, PMB 3491, Kano Tel : +234 64 66 20
50 Fax : +234 64 64 53
50 Email : |
|
4. |
Ignatius Ijantiku
Angarawai |
Programme Leader, Millet
Research (Millet Breeder) |
Lake Chad Research
Institute, Maiduguri, Nigeria |
Lake Chad Research
Institute, km 6 Gamboru-Ngala RD PMB 1293 Maiduguri, Nigeria Tel : (234)
076-231188,076-23 30 75 Email : angarawai@Yahoo.com;
emails@Yaysib.com |
|
5. |
Bill Payne |
Crop Physiologist |
Texas University |
TAES 2301 Experiment Station ND Bushland TX 19109
USA |
|
6. |
Brema Traore |
President CRU Segou |
Commission Regionale
des utilisateurs des Resultats de la Recherche Agronomique |
S/C CRRA Tel:(223) 320 35 20
55 Fax:(223) 320 35 20
49 Segou-Mali |
|
7. |
Michael Bosch |
Senior Adviser |
GTZ/BEAF |
BP. 5180 D-65762 Eschborn, Germany Tel: 49-6196-791434 Fax: 49- 6196-797137 Email Michael.Bosch@GTZ.DE |
|
8. |
Bourama Traore |
Driver |
ICRISAT |
BP 320 Bamako Tel : (223) 222 33 75
|
|
9. |
Wendy Ann Breese |
Principle investigator |
Centre For Arid Zone Studies University of Wales,
Bangor, UK |
Centre For Arid Zone Studies University of Wales,
Bangor, Gwynedd, LL57 2UW, UK Tel : +00 44 (0) 1248 38 3710 Fax: +00 44 (0) 1248
364717 Email: w.breese@bangor.ac.uk |
|
10. |
Cisse Ndiaga |
|||