International Symposium On Wheat Yield Potential - Challenges To International Wheat Breeding

Nội dung Text: International Symposium On Wheat Yield Potential - Challenges To International Wheat Breeding

1. ISBN: 970-648-144-3 M.P. Reynolds, J. Pietragalla, and H.-J. Braun, Editors International Symposium on Wheat Yield Potential: Challenges to International Wheat Breeding
2. CD—Symposium oral papers also published in journal special issues Symposium sponsors: Euphytica Relationships between height and yield in near- Genetic improvement of grain yield and associated Challenges to international wheat breeding isogenic spring wheats that contrast for major traits in the southern China winter wheat region: Australian Centre for International Agricultural Research (ACIAR). M.P. Reynolds, H.-J. Braun, J. Pietragalla, and R. Ortiz reduced height genes S.C. Chapman, K.L. 1949 to 2000 Y. Zhou, H.Z. Zhu, S.B. Cai, Z.H. He, Grains Research Development Corporation of Australia (GRDC). Sixty-two years of fighting hunger: Personal Mathews, R.M. Trethowan, R.P. Singh X.K. Zhang, X.C. Xia, G.S. Zhang recollections N.E. Borlaug International Maize and Wheat Improvement Center (CIMMYT). Partnering with farmers to accelerate adoption of Stakeholder perception of wheat production Application of new knowledge, technologies, and new technologies in South Asia to improve wheat constraints, capacity building needs, and strategies to wheat improvement M.E. Sorrells productivity G. Ortiz-Ferrara, A.K. Joshi, R. research partnerships in developing countries Organizing Committee Wheat breeding assisted by markers: CIMMYT’s Chand, M.R. Bhatta, A. Mudwari, D.B. Thapa, M.A. P. Kosina, M.P. Reynolds, J. Dixon, A. Joshi Matthew Reynolds (Chair, scientific agenda, logistics coordination). experience H.M. William, R. Trethowan, Sufian, T.P. Saikia, R. Chatrath, J.R. Witcombe, D.S. Diana Godinez (administrative support and compilation of Extended Abstracts). E.M. Crosby-Galvan Virk, R.C. Sharma Journal of Agricultural Science Rodrigo Rascón (local logistics). Yield of synthetic backcross-derived lines in rainfed Shifting undesirable correlations R.M. DePauw, Challenges to international wheat improvement Dave Poland (communications strategy). environments of Australia F.C. Ogbonnaya, G. Ye, R.E. Knox, F.R. Clarke, H. Wang, M.R. Fernandez, M.P. Reynolds, P.R. Hobbs, and H.-J. Braun R. Trethowan, F. Dreccer, D. Lush, J. Shepperd, Hans Braun (consultation). J.M. Clarke, T.N. McCaig Genetic progress in yield potential in wheat: recent M. van Ginkel The challenges of maintaining wheat productivity: advances and future prospects M.J. Foulkes, Returns to investment in new breeding technologies Pests, diseases, and potential epidemics J.W. Snape, V.J. Shearman, M.P. Reynolds, O. Gaju, Regional Coordination J.P. Brennan, P.J. Martin E. Duveiller, R.P. Singh, J.M. Nicol and R. Sylvester-Bradley Zhonghu He (China), David Bedoshvilli, Murat Karabayev, Alex Morgounov (Central Asia), High yielding spring bread wheat germplasm for global Wheat improvement in India: Present status, Prospects for increasing photosynthesis by Olaf Erenstein, Raj Gupta, Guillermo Ortiz-Ferrara, & Stephen Waddington irrigated and rainfed production systems R.P. emerging challenges and future prospects overcoming the limitations of Rubisco (South Asia), Ivan Ortiz-Monasterio, Julio Huerta-Espino & Javier Peña (Latin America ), Singh, J. Huerta-Espino, R. Sharma, A.K. Joshi, R. A.K. Joshi, B. Mishra, R. Chatrath, G. Ortiz-Ferrara, M.A.J. Parry, P.J. Madgwick, J.F.C. Carvalho, and Osman Abdalla, Hans-Joachim Braun, Arne Hede, Julie Nicol, & Sanjaya Rajaram (WANA), Trethowan R.P. Singh P.J. Andralojc High yield potential, shuttle breeding, genetic diversity, Challenges to wheat production in South Asia Dennis Friesen (Ethiopia), Pat Wall (Zimbabwe). Improving estimation of N top-dressing by and a new international wheat improvement strategy R. Chatrath, B. Mishra, G. Ortiz-Ferrara, S.K. Singh, addressing temporal variability in winter wheat R. Ortiz, R. Trethowan, A.K. Joshi K. Girma, C. Mack, R. Taylor, J. Solie, D.B. Arnall, Logistical Support G. Ortiz-Ferrara, M. Iwanaga, J.H. Dodds, J.H. Crouch, Wheat grain yield and stability assessed through and W. Raun Carmen Espinosa, Eleuterio Dorantes & Petr Kosina (visas). J. Crossa, H.-J. Braun regional trials in the Eastern Gangetic Plains of Sustainable improvement of wheat yield potential: Albertina de Gracia, Teresa Rodríguez, & Arnoldo Amaya (travel & hospitality). Lessons learnt from forty years of international spring South Asia R.C. Sharma, G. Ortiz-Ferrara, The role of crop management J.K. Ransom, Eugenio Pérez (auxiliary services). bread wheat trials R. Trethowan, J. Crossa J. Crossa, M.R. Bhatta, M.A. Sufian, J. Shoran, G.J. Endres, and B.G. Schatz Araceli Torres, Suzuky Pinto, Vania Tellez, Gemma Molero, Dolores Vázquez & A.K. Joshi, R. Chand, G. Singh, R. Ortiz Understanding the physiological basis of yield Carolina Saint-Pierre (registration). potential in wheat R.A. Fischer Use of spatial analyses for global characterization of wheat-based production systems D.P. Hodson, Facilitation of Symposium Sessions and J.W. White Norman E. Borlaug (former CIMMYT Wheat Director). Conservation agriculture: What is it and why is it Tony Fischer (former CIMMYT Wheat Director and ACIAR sponsor representative). important for future sustainable food production? Sanjaya Rajaram (former CIMMYT Wheat Director and ICARDA BIGM P.R. Hobbs Program and ICWIP Director). Association of source/sink traits with yield, biomass Masa Iwanaga, CIMMYT Director General. and radiation use efficiency among random sister lines from three wheat crosses in a high-yield John Dixon (CIMMYT Director, ITAU). environment M. P. Reynolds, D. Calderini, Jonathan Crouch (CIMMYT Director, GRU). A. Condon, and M. Vargas Hans Braun (CIMMYT Wheat Director). Sink limitations to yield in wheat: How could they be Petr Kosina (CIMMYT Training). reduced? D.J. Miralles, and G.A. Slafer Tom Payne (CIMMYT Wheat Germplasm Bank). Structural equation modelling for studying genotype David Poland (CIMMYT Science Writer). x environment interactions of physiological traits affecting yield in wheat M. Vargas, J. Crossa, M.P. Reynolds, P. Dhungana, K.M. Eskridge Editing: Alma McNab, Mike Listman, Dave Poland An economic assessment of the use of physiological Design, layout, and production: Miguel Mellado, Eliot Sánchez, Marcelo Ortíz, Antonio Luna, selection for stomatal aperture-related traits in and Wenceslao Almazan the CIMMYT wheat breeding programme J.P. Brennan, A.G. Condon, M. van Ginkel, and M.P. Reynolds U-impact pathway for diagnosis and impact assessment of crop improvement J. Dixon, J. Hellin, O. Erenstein, and P. Kosina Conservation agriculture in South Asia R. Gupta, and K.D. Sayre Reduced nitrogen and improved farm income for irrigated spring wheat in the Yaqui Valley, Mexico, using sensor-based nitrogen management J.I. Ortiz-Monasterio, and W. Raun
3.     International Symposium on   Wheat Yield Potential:  Challenges to International Wheat Breeding M.P. Reynolds, J. Pietragalla, and H.‐J. Braun,  Editors 
4. CIMMYT® (www.cimmyt.org) is an internationally funded, not-for-profit organization that conducts research and training related to maize and wheat throughout the developing world. Drawing on strong science and effective partnerships, CIMMYT works to create, share, and use knowledge and technology to increase food security, improve the productivity and profitability of farming systems, and sustain natural resources. Financial support for CIMMYT’s work comes from many sources, including the members of the Consultative Group on International Agricultural Research (CGIAR) (www.cgiar.org), national governments, foundations, development banks, and other public and private agencies. © International Maize and Wheat Improvement Center (CIMMYT) 2008. All rights reserved. The designations employed in the presentation of materials in this publication do not imply the expression of any opinion whatsoever on the part of CIMMYT or its contributory organizations concerning the legal status of any country, territory, city, or area, or of its authorities, or concerning the delimitation of its frontiers or boundaries. CIMMYT encourages fair use of this material. Proper citation is requested. Correct citation: Reynolds M.P., J. Pietragalla, and H.-J. Braun, eds. 2008. International Symposium on Wheat Yield Potential: Challenges to International Wheat Breeding. Mexico, D.F.: CIMMYT. ISBN: 970-648-144-3 AGROVOC descriptors: Wheat; Food production; Food supply; Plant breeding; Genotype environment interaction; Agroecosystems; Adaptation; Trials; Yields; South Asia; Brazil; China; Ethiopia; India; Mexico; Turkey; Zimbabwe AGRIS category codes: E10 Agricultural Economics and Policies F30 Plant Genetics and Breeding Dewey decimal classification: 633.1153 REY Printed in Mexico. ii
5. Contents v Foreword 1 International Wheat Improvement: Highlights from an Expert Symposium M.P. Reynolds, P. Hobbs, R. Ortiz , J. Pietragalla, and H.-J. Braun Workshop 8 Stakeholders’ priorities for internationally-coordinated wheat research M.P. Reynolds, J. Dixon, K. Ammar, P. Kosina, and H.-J. Braun Field Day 18 A worldwide wheat research network: Highlights from field day presentations of the international wheat yield symposium M.P. Reynolds Country abstracts and posters 23 Argentina 27 Azerbaijan 30 Bangladesh 35 Brazil 39 China 43 Egypt 45 Ethiopia 49 India 54 Iran 59 Kazakhstan 64 Kyrgyzstan 66 Mexico 70 Morocco 74 Nepal 79 Pakistan 82 Sudan 87 Tajikistan 91 Turkey 95 Uzbekistan 99 Zimbabwe iii
6. Oral presentations (not previously published in journal special issues) 103 Wheat yield potential S. Rajaram, and H.-J. Braun 108 Association among durum wheat international testing sites and trends in yield progress over the last twenty-two years K. Ammar, J. Lage, D. Villegas, J. Crossa, H. Hernandez, and G. Alvarado 113 Using plant breeding data to move from genotype-by-environment interactions to gene-by-environment interactions H.A. Eagles, K. Cane, D.B. Moody, R.F. Eastwood, G.J. Hollamby, H. Kuchel, and P.J. Martin 120 Exploitation of genetic resources through wide crosses M. Kishii, R. Delgado, V. Rosas, A. Cortes, S. Cano, J. Sanchez, and A. Mujeeb-Kazi 126 Stomatal aperture related traits and yield potential in bread wheat A.G. Condon, M.P. Reynolds, J. Brennan, M. van Ginkel, R. Trethowan, G.J. Rebetzke, D.G. Bonnett, R.A. Richards, and G.D. Farquhar 134 Complementing the breeder’s eye with canopy temperature measurements M. van Ginkel, M.P. Reynolds, R. Trethowan, E. Hernandez 136 Source and sink traits that impact on wheat yield and biomass in high production environments M.P. Reynolds, J. Pietragalla, T.L. Setter, and A.G. Condon 148 Raised bed planting technologies for improved efficiency, sustainability and profitability K. D. Sayre, A. Limon-Ortega, and R. Gupta 161 Avenues to increase yield potential of short season, high latitude wheat in Northern Kazakhstan and Siberia A. Morgounov, R. Trethowan 167 Challenges to wheat production in Brazil P.L. Scheeren, E. Caierão, M.S. Silva, A.J. Nascimento, V.R. Caetano, M.C. Bassoi, D. Brunetta, J.C. Albrecht, W.J. Quadros, P.G. Sousa, M.G. Trindade, J.S. Sobrinho, S. Wiethölter, and G.R. Cunha 171 Improving or preserving bread making quality while enhancing grain yield in wheat R.J. Peña 175 Innovation systems and impact pathways for wheat J. Dixon, J. Hellin, O. Erenstein, P. Kosina, and L.L. Nalley 181 Agricultural R&D spending at a critical crossroads P. Pardey, J. Alston, and N. Beintema 190 Summary of evaluation questionnaire for the International Symposium on Increasing Wheat Yield Potential Petr Kosina 192 List of participants On CD: Symposium oral papers also published in journal special issues iv
7. Foreword Like many other patterns, investment in research is often cyclical. International centers like CIMMYT have focused substantial resources on biotic and abiotic stresses for about two decades now, but raising total productivity is also back on the development agenda. There are a number of reasons for this, among them sharp rises in the price of staple foods as well as the manifestation of detrimental effects of climate change on productivity. Those factors threaten not only the livelihoods of resource-poor people but food security at a broader level, as highlighted by the World Bank’s recent World Development Report. CIMMYT has an unsurpassed record when it comes to raising crop yields from the days of the Green Revolution; as can be seen from the comprehensive scope of this new publication, our Global Wheat Program is back in the game. The book consists of proceedings of a week-long consultation of experts and leaders held in 2006 and representing all major wheat producing countries worldwide. It encompasses their ideas on how, through internationally coordinated collaborative research, proven technologies of the past can be married with new tools and approaches to meet demand for the world’s number one staple crop: wheat. Masa Iwanaga Director General CIMMYT v
8. vi
9. International Wheat Improvement: Highlights from an Expert Symposium M.P. Reynolds, P. Hobbs, R. Ortiz , J. Pietragalla, and H.-J. Braun (i) Reports of a one day workshop entitled “Stakeholder Introduction priorities for internationally-coordinated wheat Wheat is grown on 217 million hectares throughout the research” involving representatives of major wheat world, which produced approximately 620 million tons of producing countries on all continents whose remit was grain annually during the period 2004-2006 (FAO, 2007) to develop: (a) a list of priorities for future wheat and provided, on average, one-fifth of the total calorific research that could best be tackled in a globally- input of the world’s population (FAO, 2003). In regions coordinated fashion, and (b) outlines of activities that such as North Africa, Turkey, and Central Asia, wheat would serve as templates for future project provides half of total dietary calories, for example, 1500 development for selected priorities (Reynolds et al. A). (ii) The summary of field day presentations given by kcal per capita per day in Iran. Of the cultivated wheat area, groups of collaborating scientists in attendance half is located in less developed countries where there have illustrating the continuum between national, regional, been steady increases in productivity since the green and international-center-based research activities revolution, associated with genetic improvements in yield (Reynolds). potential, resistance to diseases, adaptation to abiotic (iii) Reports of a pre-symposium survey soliciting statistics stresses, and better agronomic practices (Reynolds and on wheat production and constraints to productivity Borlaug, 2006a and b). Nonetheless, challenges to wheat and research from 19 countries in Latin America, Sub- production are still considerable, especially in the Saharan Africa; Central and West Asia and North developing world, not only because of increased demand Africa; and South and Southeast Asia (see Country but also because of the increased scarcity of water resources Surveys). Collectively these countries represent over (Shiklomanov and Rodda, 2003) ever more unpredictable 100 million ha of wheat and around 90% of the wheat climates (Fischer et al., 2002), increased urbanization and production in developing countries (FAO, 2006). These loss of good quality land away from agriculture (Hobbs, on data were also used to prepare a general summary of CD, JAS), and decreased public sector investment in the constraints to productivity and research across all agriculture and rural affairs (Falcon and Naylor, 2005). To of the above mentioned regions (Kosina et al., on CD, meet demand in a sustainable way, more resources are Euphytica). required to breed a new generation of genetically improved cultivars as well as implement resource conserving agronomic management practices. Summary of the Plenary Presentation A symposium was organized by the International Maize and The symposium was opened with an address by Nobel Wheat Improvement Center’s Global Wheat Program, with Laureate Dr. Norman Borlaug (on CD, Euphytica) entitled support from the Australian Centre for International “Sixty-two years of fighting hunger: Personal Agricultural Research (ACIAR), in Ciudad Obregon, recollections.” Dr. Borlaug described the evolution of northwestern Mexico, in March 2006. The aim of this international wheat breeding including how shuttle breeding symposium was to bring together wheat researchers was adopted in Mexico, enabling photoperiod sensitivity to worldwide to present and discuss their ideas on how to be overcome, a pivotal step in creating internationally address some of the pressing issues of increasing wheat adapted germplasm. His talk touched on a number of production in a sustainable manner. Participants included historical yet topical issues, including how the 15b stem 160 scientists from over 30 wheat producing countries. rust epidemic in the US in the 1950s is being mirrored 50 Many of the ideas presented at the symposium have already years later by the virulent new race Ug99 from East Africa; been published in 2007 (and are faithfully reproduced in the evolution of internationally coordinated public goods this volume) in special issues of Euphytica (volume 157: 3) research in agriculture, which led to the formation of the and Journal of Agricultural Science, Cambridge (volume CGIAR (Consultative Group of International Agricultural 145: 1-3). Highlights of these papers, along with a number Research), a system which despite its humanitarian mandate of oral papers published for the first time in this book, are and many successes suffers from declining investment that summarized below. In addition, this volume documents the is eroding the promise of food security for many of the following symposium and pre-symposium activities: world’s most resource-poor people. He specifically addressed high yield agriculture and the environment, agro- 1
10. forestry, drought tolerance, the promise of biotechnology, Value of Internationally Coordinated Breeding Efforts bureaucracies, and fear of change, and finished with a quote from 1949 Nobel Peace Prize winner Lord John Boyd The paper presented by Rajaram and Braun (p. 103, these Orr, “World peace will not be built on empty stomachs.” proceedings) reviewed efforts conducted over the last 50 years to increase yield potential gains while improving adaptation to biotic and abiotic stresses. While percent Latest Technologies gains have been similar in irrigated and rainfed areas in Sorrels (on CD, Euphytica) reviewed impacts of new absolute figures, productivity has increased considerably technologies in his article “Application of new knowledge, more in irrigated areas. Rajaram and Braun underscored the technologies, and strategies to wheat improvement.” He need to develop new germplasm with adaptation to abiotic highlights the complexity of the genomes of graminaceous stresses without sacrificing yield potential, so that farmers crops and the fact that they are rapidly evolving and benefit in favorable years. A good example is Attila, a line heterogeneous, even within species. Not surprisingly, the that has been reselected or released in countries with highly use of marker-assisted selection for improving complex contrasting environments. They also emphasized the traits remains one of the challenges facing wheat breeders. importance of introducing new genetic diversity. For Progress in recent years includes new transformation example, results from Wheat International Nurseries protocols, statistical methods, methods for characterizing distributed by CIMMYT have shown that cultivars with environments, and equipment for phenotyping traits. Sorrels 1B/1R are better adapted to lower input conditions, and also mentions progress in the area of molecular markers and other translocations such as 1A/1R, 7DL/7AG have already microarray applications, gene silencing protocols, DNA shown beneficial effects on yield potential in a range of sequencing, and transgenic crops. Comparative mapping genetic backgrounds. and QTL studies have provided information about the location, identity, and number of genes controlling some To meet future demands for wheat, all available economically important traits. technologies must achieve an annual yield increase of about 2% until 2020. Singh et al. in their article “High yielding The articles by William et al. and Ogbonnaya et al. (on spring bread wheat germplasm for global irrigated and CD, Euphytica) review advances at the frontiers of wheat rainfed production systems” (on CD, Euphytica) report that improvement research, namely, the use of molecular grain yields of the best new entries were 10% higher than breeding tools and wild species for re-synthesizing wheat. the local checks in international yield trials. While not all William et al. argue that markers are now being used to genotypes respond as well across sites, analysis of genotype better characterize parental lines, improve the effectiveness × environment interaction provides opportunities to select of crossing strategies, and track genes in segregating for stable genotypes. As outlined by Ortiz et al. (on CD, progenies. Although still costly, marker-assisted selection JAS), international wheat improvement at CIMMYT has (MAS) appears to be routinely used for a few traits by included shuttle breeding at two contrasting locations in wheat breeding programs worldwide. The genetic potential Mexico to facilitate selection of genotypes with wide of re-synthesized hexaploid germplasm (when crossed to adaptation and durable resistance to rust and Septoria, elite cultivars) was investigated by Ogbonnaya et al. They while incorporating as wide a range of genetic diversity as found that such synthetic-derived lines yielded 8-30% possible into the thousand or so new entries that are higher than the best local check in multi-site trials across distributed in international nurseries annually. Their article diverse regions of Australia. Their results reinforce points out that CIMMYT’s primary generic target product previous research conducted at CIMMYT that found that has been “genetically enhanced seed-embedded lines derived from synthetic wheat have the potential to technology” which considers both strategic germplasm significantly improve grain yield across environments. enhancement and adaptive breeding to mega-environments. Kishii et al. (p. 120, these proceedings) reiterate the idea It discusses whether CIMMYT and similar CGIAR centers that a great number of useful genes in ancestral wheat will in the future invest more resources in strategic species could be transferred into wheat, based on previous germplasm enhancement, while adaptive breeding would be CIMMYT efforts using wild relatives, including Ae. conducted progressively more by national agricultural tauschii, T. monococcum, T. dicoccoides, and T. timopheevi. research systems (NARSs). (Strategic germplasm However, Brennan and Martin’s article “Returns to enhancement would include identification and utilization of investment in new breeding technologies” (on CD, novel genetic variation, e.g. from landraces and wild Euphytica) advocates that breeding programs should species––including production of re-synthesized wheat.) carefully assess the likely economic returns from the value Given the mission of IARCs within the international of incorporating new approaches into their programs, a development assistance community, if their products are to decision that is likely to be based on the scale of the change significantly, they must consider the needs and breeding operation, with low cost investments being more relative strength of NARSs on a case by case basis. universally accessible. 2
11. The article by Trethowan and Crossa (on CD, Euphytica) in participatory varietal selection, thereby extending the analyzed 40 years of international spring bread wheat trials. potential impact of international public goods germplasm. The analysis confirmed the relevance of shuttle breeding Advances in wheat improvement must also consider between two locations in Mexico for global wheat wheat’s final end-uses. Negative correlations between grain improvement, since selection environments generated in yield, grain protein concentration, and final end-use are Mexico associate well with global target areas. They described by De Pauw and his colleagues in the article describe how integrating information from international “Shifting undesirable correlations” (on CD, Euphytica). sites with that obtained in Mexico helps to improve the They concluded that the undesirable correlations of grain efficiency of CIMMYT’s global wheat breeding effort. For yield, grain protein concentration, and time to maturity can more than 40 years, cooperating breeders from many be shifted by developing plants, which efficiently produce countries have grown these trials, provided their elite and partition carbohydrates to grain yield and have germplasm, and returned data to CIMMYT, which has improved nitrogen- and water-use efficiency. Improvements made the compiled results available to all cooperators. in these traits could also be transferred to wheat cultivars in Ammar et al. (p. 108, these proceedings) also highlighted water- and nitrogen-deficient areas. They showed that the successes of the international durum wheat yield trial simultaneous selection for quantitative and quality traits over the last 22 years, based both on the shuttle-breeding with the inclusion of marker-assisted selection, can shift approach and the global network of NARS cooperators for these undesirable correlations. Echoing previous statements information feedback. Without this unprecedented global on the value of wild species, Peña (p. 172, these cooperation, none of the impacts (for example, in proceedings) remarks that introducing protein-enhancing improving yield under favorable and marginal genes from Triticum dicoccoides is a strategy to increase environments and enhancing disease resistance) would have grain protein content while simultaneously tackling the been possible. inherent problem of improving both grain yield and grain quality. The articles by Chapman et al. and Ortiz-Ferrara et al. (on CD, Euphytica) assess the advantages of using a global Addressing a subject worthy of a symposium in its own approach by incorporating key genes (e.g., for plant height) right, Duveiller and coauthors (on CD, Euphytica) present in wheat breeding lines and emphasizing regional efforts strategies aimed at minimizing or controlling yield losses through participatory research and client-oriented plant from major diseases and pests relevant to intensive irrigated breeding, respectively. In the article “Relationships between wheat systems in the developing world. Options suggested height and yield in near-isogenic spring wheats that contrast include integrated crop management practices; breeding for for major reduced height genes” Chapman and co-authors genetic resistance; rotations; minimizing physiological showed how the environment influenced the phenotypic stresses and consequent susceptibility by timely sowing and effects of two major dwarfing genes (Rht1 and Rht2). Their adequate use of fertilizers; and fungicide application. In results confirm the advantage of incorporating such genes their article “The challenges of maintaining wheat in wheat cultivars, since there was a ca. 10% yield gain for productivity: pests, diseases, and potential epidemics,” they lines possessing such genes, which was more evident in also advise about the risk of changes in disease spectra as a trials where the mean height of semidwarf isolines result of climate changes and demonstrate the complex exceeded about 80 cm. Genotype-by-environment relationships among crop physiology, disease resistance, interaction, especially of the cross-over type, was identified and yield. by participants at the symposium as a major concern, impeding improvement especially of quantitative traits. Regional Challenges Eagles et al. (p. 103, these proceedings) suggested that Several papers addressed wheat improvement in major molecular and statistical technologies can be used to assist grain baskets around the world: Joshi and co-workers (on breeding for polygenic traits such as yield. Large data sets CD, Euphytica) point out that India “faces a critical of the type generated by plant breeding programs are challenge in maintaining food security in the face of its necessary, along with a large-scale genotyping of national growing population.” Indian wheat breeders should and international entries via available markers. therefore aim to improve the crop to address heat stress Ortiz-Ferrara et al., in their article “Partnering with farmers (exacerbated by global warming due to climate change); to accelerate adoption of new technologies in South Asia to water scarcity due dwindling water supplies for irrigation; improve wheat productivity,” describe how several farmer- the growing threat of new virulence in diseases such as preferred technologies have been identified for adverse wheat rusts and leaf blight; continuous adoption of zero-till conditions in eastern India and Nepal. Due to this and other resource conservation technologies, particularly participatory-research approach, grain harvests by resource- in the intensive and highly productive rice-wheat systems; poor farmers significantly increased (15-70%) in locations and a high demand for better quality wheat. Challenges to where farmers, scientists, extension specialists, non- wheat production in South Asia in terms of biotic and governmental organizations, and the private sector engaged abiotic stresses are also described by Chatrath et al (on 3
12. CD, Euphytica). They point to stagnating wheat yields and To gain an overview of the constraints that breeders are the declining productivity of wheat-rice systems due to facing, a survey was conducted covering 19 countries, intensive tillage and burning of residues, which lead to the representing 90% of all wheat grown and produced in less depletion of soil organic carbon. Excessive nutrient mining, developed countries (Kosina et al., on CD, Euphytica). The imbalanced fertilization and over-exploitation of water most significant constraints to wheat production were resources are the other factors responsible for declining reported to be heat and water stress, weeds, and diseases. productivity. Addition of organic matter to soil through Access to mechanization and credit availability were the green manuring and crop residue recycling, balanced socioeconomic constraints most often highlighted. Lack of fertilization, integrated nutrient management, and crop resources for field station operations is an important diversification is suggested to improve total productivity in infrastructural constraint. The most desired outputs from the region (see also Gupta and Sayre [on CD, JAS] for partnerships with international agricultural centers include their analysis of the benefits of conservation agriculture in germplasm development and exchange, assistance in the region). capacity building, and knowledge sharing. Identification of wheat genotypes with high and stable grain Progress in Understanding the Physiological Basis of yield is of particular relevance for poor farmers. Sharma et Yield al. (on CD, Euphytica) report results for the Eastern Gangetic Plains Yield Trials, grown in India, Nepal, and Two papers (Fischer; Foulkes et al., on CD, JAS) review Bangladesh from 1999 to 2005. Lines with improved yield recent work on the physiological basis of genetic increases stability and disease resistance were identified and released, in wheat yield potential, with the latter focusing more on which underlines the importance and relevance of regional winter wheat. Data from the last 10 years in northwestern wheat breeding programs. Similarly, Zhou et al. (on CD, Mexico indicate that yield potential progress in CIMMYT Euphytica) evaluated genetic gains for grain yield in two spring wheat has slowed to around 0.50% per year although regions of the Southern China Winter Wheat area, using physiological understanding has advanced. New research leading cultivars released from 1949 to 2000. Results reinforces the importance of spike dry weight (g/m2) at showed average annual genetic gain of about 0.31% and anthesis in yield determination, and lengthening the spike 0.74%, respectively. In region 1, yield components did not growth period through manipulation of photoperiod change, though plant height was reduced; in region 2 sensitivity looks promising, a subject which is addressed in genetic improvement of grain yield was attributed to more depth in the paper by Miralles and Slafer (on CD, increased thousand-kernel weight (0.65%, P<0.01) and JAS). Despite producing more kernels/m2, the latest wheat kernel weight/spike (0.87%, P<0.01). The future challenge cultivars still appear to be largely sink-limited during grain of wheat breeding in this region is to continue improving filling, while evidence from wheat and other cereals grain yield and disease resistance, and to develop cultivars indicates the importance of increased photosynthetic suitable for wheat/rice double cropping under reduced activity before and during flowering to achieve increases in tillage. yield potential (see also Reynolds et al., p. 136, these proceedings). Fischer highlights the need to better define Morgounov and Trethowan (p. 162, these proceedings) and utilize traits that confer lodging resistance. He also reviewed recent work in the short-season, high-latitude refers to recent advances in techniques for elucidating the areas of Northern Kazakhstan and Siberia, where yield physiological basis of genotype × year interactions. This is potential is limited by lack of moisture in the dry years and specifically addressed in the paper by Vargas et al. (on CD, by leaf rust in years with sufficient precipitation. They JAS). Path analysis for genotype × environment interactions focused on three main approaches that would be required to using structural equation modelling enables a number of maximize yield in the region: improved agronomic response variables to be modelled simultaneously while practices, better adapted germplasm, and policy partitioning significance to interaction with specific weather interventions, especially for the former. They conclude that parameters during the growth cycle. application of zero and minimal tillage would provide a sustainable alternative to avoid the erosion caused by Foulkes et al. point to the increasing number of reports of current management practices. In a similar vein, Scheeren yield progress that is associated with biomass (in contrast to et al. (p. 168, these proceedings) explain the main previous associations with partitioning alone). In winter challenges to wheat production in Brazil, highlighting the wheat, recent biomass progress was related to pre-anthesis importance of agronomic practices, improved varieties, and radiation-use efficiency (RUE) and water-soluble management policies in order to increase yield potential. carbohydrate (WSC) content of stems at anthesis. They also Pardey et al. (2006) remarked that some developing highlight the value of introductions of alien genes into countries are becoming more self-reliant and are creating wheat germplasm (e.g., the 1BL.1RS wheat-rye their own research and development programs; however, translocation and the 7DL.7Ag wheat-Agropyron the more disadvantaged countries will struggle to maintain elongatum translocation). Foulkes et al. provide a list of productivity growth in the face of declining spillovers. traits that their analysis has identified as high potential 4
13. candidates to raise winter wheat yield potential in isotope discrimination, in early generations of the northwestern Europe, including: optimized rooting traits, an CIMMYT wheat breeding program, to break barriers to extended stem-elongation phase, greater RUE, greater stem bread wheat yield potential. The results indicated WSC storage, and optimized ear morphology. considerable potential in the use of those tools to complement breeders’ visual selection for high yield Miralles and Slafer and Reynolds et al. consider the issue of potential lines. Similar results are reported by van Ginkel sink and source limitations in some detail. The former et al. (p. 134, these proceedings), who focused on the use of sketch out evidence, a considerable amount of which has canopy temperature depression during the selection of been produced by Argentinean scientists, that further segregating generations to positively skew gene frequency increases in grain number/m2 may be achieved through for yield and adaptation. Their study made it evident that fine-tuning pre-anthesis developmental patterns to increase the combination of canopy temperature depression with duration of the rapid spike growth period (RSGP) without visual selection improves the rate of genetic progress and altering flowering time. They report that there is genotypic was the approach that identified lines with the highest yield variation in the relative duration of phenophases prior to potential. Parallel studies have shown that a number of anthesis and that theoretically photoperiod sensitivity could spectral reflectance indices also have considerable potential be manipulated to slow down and, therefore, prolong the in selecting for yield (Babar et al., 2006a) and biomass floret primordial stage to achieve more fertile florets. (Babar et al., 2006b) in random inbred lines and advanced However, genetic understanding is limited, and QTL breeding lines. However, one of the aims of applying a analysis is indicated to identify genetic markers for which physiological or, for that matter, a molecular marker in they and their colleagues have already provided a breeding is to increase the efficiency of selection by substantial background of phenotypic data. The study by reducing costs or increasing turnover. One of the papers Reynolds et al. looks at both source and sink (SS) limitation presented an economic assessment of the use of in populations of random sister lines to establish a more physiological selection for stomatal aperture-related traits in definitive link of SS traits with productivity. The SS traits CIMMYT’s wheat breeding program (Brennan et al., on formed three main groups relating to (1) phenological CD, JAS) The analysis lent strong support to their potential pattern of the crop, (2) assimilation capacity up until shortly value for reducing costs, for example, by discarding after anthesis, and (3) partitioning of assimilates to physiologically substandard lines prior to extensive yield reproductive structures shortly after anthesis. The largest testing. genetic gain in performance traits was associated with the Agronomic and Environmental Strategies for Raising second group; however, traits from the other groups were and Sustaining Productivity also identified as being genetically linked to improvement in yield and biomass. Principal component analysis While CIMMYT and other research groups within the indicated potential for additive genes if complementary CGIAR have made major contributions to agricultural physiological traits are combined through breeding. development, experts in geographical information systems (GIS) postulated that the continued ability to make far- Parry et al. (on CD, JAS) considered the issue of reaching contributions can only be achieved by an increased increasing assimilation capacity at the cellular level through ability to collect, analyze, and assimilate large amounts of overcoming the limitations of Rubisco. Low activity and spatially oriented agronomic and climatic data (Hodson the competing reactions catalyzed by Rubisco are major and White, on CD, JAS). They state that understanding the limitations to photosynthetic carbon assimilation in C3 geographic context of wheat production is crucial for plants, and they present the latest evidence that these could priority setting, promoting collaboration, and targeting be most effectively addressed by introducing Rubisco with germplasm or management practices to specific a higher catalytic rate and/or a greater capacity to environments. They describe how modern GIS techniques discriminate between gaseous substrates. Although can be used to help predict the effects of climate change enzymes with desirable traits have been identified, the and classify production environments by combining technology is not available to incorporate them into crop biophysical and socioeconomic criteria. Regional-scale species. Parry et al. also suggest another approach via modelling of dynamic processes such as disease increasing the concentrations of substrates, CO2, and progression or crop water status provide, in combination Ribulose biphosphate (RuBP) at the active site of Rubisco, with socioeconomic forecasting, a set of predictive tools much as in C4 plants. that can be applied in determining priorities for genetic improvement. They are equally applicable for developing Another issue addressed at the symposium was the use of long-term cropping systems strategies aimed at maximizing physiological selection criteria for high yield environments. the productivity of agro-ecosystems through the application Condon et al. (2007, p. 126, these proceedings) of appropriate conservation agricultural practices that summarized the results of a project aimed to evaluate the incorporate local microeconomic factors (Dixon et al., use of physiological traits related to stomatal aperture, such 2007, p. 176, these proceedings). as canopy temperature, leaf conductance, and carbon 5
14. Conservation agriculture (CA) is a resource conserving surface, and diversify crop rotations resulting in the same agronomic management practice that combines minimal physical, biological, and chemical benefits outlined in the soil disturbance (no-till) and permanent soil cover (mulch) Hobbs paper. with rotations. Hobbs (on CD, JAS) describes the practice Reduced fertilizer use efficiency can result in unnecessary and why it is important for future food production. It is an costs to farmers but also negative effects on the improvement on conservation tillage which is best environment (pollution of groundwater). With a likely described as an intermediate step from normal tillage increase (largely due to rising fossil fuel prices) in nitrogen agriculture and CA where minimal tillage is combined with fertilizer costs to farmers anticipated in the next few years, mulch to reduce wind and water erosion and increase water increased nitrogen use efficiency (NUE) is needed for infiltration into the soil. The paper goes on the describe the future food production. Two papers, Ortiz-Monasterio and physical, biological, and chemical benefits of CA, which is Raun and Girma et al. (on CD, JAS), look at ways to now practiced (no-till acreage) on almost 100 million ha in improve NUE in wheat. The Ortiz-Monasterio and Raun the world, especially in the South American countries of paper is based on data collected from the Yaqui Valley in Brazil and Argentina. Additional benefits are economic northwestern Mexico, where nitrogen-use efficiency has (less cost and yields at least equal to those of traditional been estimated to be only 0.31. They evaluated the use of farming) and social (less time). The paper also explains the N-rich strips together with the GreenSeeker™ sensor and a importance of developing suitable equipment to enable farmers to adopt this green technology. Ransom et al. (on crop algorithm as a tool to improve NUE in spring wheat CD,JAS) describe a similar no-till, crop rotation system for against conventional farmer use of nitrogen. The results dryer regions of North Dakota that results in significant showed, on average, that farmers could save 69 kg N/ha yield increases and protects the productivity of the soil. without a yield penalty; this represents a saving of They did not find similar results for the wetter areas of US$ 62/ha. On fields larger than 10 ha, farmers could North Dakota but did show the benefits of fungicide improve farm income by US$ 50/ha just using the application for scab control. They conclude that identifying GreenSeeker™ sensor technology. Girma et al. used the or developing crop management practices that exploit same GreenSeeker™ normalized difference vegetation positive genotype × management interactions is needed. index (NVDI) sensor, calibration stamp (CS), N-rich strips, and ramped calibration strips (RCS) to improve top-dress Conservation agriculture is also becoming popular in South nitrogen efficiency in winter wheat in Oklahoma, USA. Asia in the rice-wheat systems of the Indo-Gangetic Plains They obtained similar benefits and conclude that the (IGP). Gupta and Sayre (on CD, JAS) use this case study simplicity of these technologies means they can be readily as an example of improved resource conservation applied by farmers in developed and developing countries. technologies (RCTs) that have led to improved profits and The RCS method is designed to include more pre-plant N yields, and have impacted various environmental factors and is more efficient at predicting top-dress N needs. when zero-till was applied to wheat following rice harvest. Farmers were encouraged by the results, and in 2005-2006 The adoption of new technologies by farmers is a season nearly 3 million hectares of wheat were planted this prerequisite for achieving the potential of improved way. The paper describes various RCTs that have been germplasm and crop management and improving introduced in the past 10 years, including laser levelling, livelihoods and environmental benefits that would crop diversification, and even promising results with no-till contribute substantially to the UN’s Millenium and direct seeded rice; the latter is important for ‘double’ Development Goals (MDG). Dixon et al. (2007, on CD, no-till systems and better soil physical and biological JAS) draw on a wide spectrum of recent literature for properties. understanding the pathways and processes for adoption of improved technology and the measurement of impact. The Raised bed planting technologies are a further improvement paper looks at input value chains, farm household on CA on the flat. Sayre et al. (p. 148, these proceedings) characteristics, and an output value chain that can be use data collected in the Yaqui Valley in northwestern visualized as a U-impact pathway to determine the rate and Mexico as a case study of the findings of this technology in extent of adoption of improved varieties and practices, the an irrigated wheat-maize system in a long-term trial (15 magnitude of impacts, and the potential for feedback loops years). Farmers in the Yaqui Valley have mostly shifted to leading to improved functioning of agricultural innovation planting irrigated wheat (and most other crops) on beds systems and input-output chains. The U-impact pathway rather than on the flat (with basin irrigation), but still use proposed in the paper provides a framework to identify a set conventional tillage. Bed planting was adopted because of of beneficiaries that extends beyond producers and the 30-40% savings in water use. Sayre et al. present consumers, and that can be mapped using participatory convincing data to show that it is feasible for permanent, methods to identify sources of the wider benefits of raised beds and conservation agriculture technologies to technology. The results suggest that the benefits accruing to provide opportunities to dramatically reduce tillage, save agricultural research may be greater and more widely water and costs, manage retained residues on the soil distributed across the economy than previously recognized, 6
15. and strengthen the case for increased investment in References agricultural science. Babar, M.A., Reynolds, M.P., van Ginkel, M., Klatt, A.R., Raun, W.R., and Stone, M.L. 2006a. Spectral reflectance indices as Concluding Remarks a potential indirect selection criteria for wheat yield under irrigation. Crop Science 46:578-588. The symposium simultaneously highlighted reasons to be Babar, M.A., Reynolds, M.P., van Ginkel, M., Klatt, A.R., Raun, optimistic about improving the impact of wheat breeding W.R. and Stone, M.L. 2006b. Spectral reflectance to estimate through adoption of new technologies, while underscoring genetic variation for in-season biomass, leaf chlorophyll and the considerable challenges faced by agricultural canopy temperature in wheat. Crop Science 46:1046-1057. researchers due increased demand for wheat as well as Condon, A.G., Reynolds, M.P., Rebetzke, G.J., van Ginkel, M., environmental and economic constraints. The slow though Richards, R., and Farquhar, G. 2007. Using stomatal aperture-related traits to select for high yield potential in steady rate of yield potential increase in wheat is bread wheat. In: Wheat Production in Stressed Environments. insufficient to meet predicted global demand. In the last two H.T. Buck, J.E. Nisi, and N. Salomón (eds.). Series: decades, however, research has made significant progress in Developments in Plant Breeding, Vol. 12. New York: a number of areas, which, if brought to a common platform, Springer. have the potential to achieve substantial increases in Dixon, J., Hellin, J., Erenstein, O., and Kosina, P. 2007. U-impact productivity at the farm level. These fields include (1) pathway for diagnosis and impact assessment of crop improved understanding of the physiological basis of yield improvement. Journal of Agricultural Science 145:195-206. in wheat, (2) genetic tools that would permit markers for Falcon, W.P., and Naylor, R.L. 2005. Rethinking food security for traits associated with improved yield to be rapidly the twenty-first century. American Journal of Agricultural Economics 87:1113-1127. developed, (3) a new generation of statistical tools which FAO. 2003. FAO Production Statistics. Published online at: permit genotype × environment interaction to be dissected http://faostat.fao.org/site/567/DesktopDefault.aspx?PageID= into its genetic and physiological components, and (4) a 567 (verified 19/2/07). rapidly increasing body of practical knowledge on how to FAO. 2005. FAO Production Statistics. Published online at: implement conservation agriculture practices that would http://faostat.fao.org/site/567/DesktopDefault.aspx?PageID= both raise and stabilize the environmental threshold on 567 (verified 19/2/07). which genetic yield potential is expressed. An international Fischer, G., Shah, M., and Van Veltuizen, H. 2002. Climate center such as CIMMYT, with its expertise in germplasm Change and Agricultural Variability. Laxemburg, Austria: development, phenotyping, strategic agronomy, use of IIASA. Pardey, P., Alston, J., and Beintema, N. 2006. Agricultural R&D statistical models, and practical application of molecular spending at a critical crossroads. Farm Policy Journal 3(1):1- markers in breeding, in addition to its well developed 9. network of scientists in national programs and advanced Reynolds, M.P., and Borlaug, N.E. 2006. Impacts of breeding on research laboratories around the world, is strategically international collaborative wheat improvement. Journal of positioned to provide a focal point for these disciplines. Agricultural Science 144:3-7. Reynolds, M.P., and Borlaug, N.E. 2006. Applying innovations and new technologies for international collaborative wheat improvement. Journal of Agricultural Science 144:95-110. Shiklomanov, I.A. & Rodda, J.C. 2003 (eds) World water resources at the beginning of the 21st Century. International Hydrology Series, Cambridge: CUP, 450pp. 7
16. Stakeholders’ Priorities for Internationally-Coordinated Wheat Research M.P. Reynolds, J. Dixon, K. Ammar, P. Kosina, and H.-J. Braun Reviewers • Izzat S. A. Tahir, National Wheat Coordinator, ARC, Sudan • K.E. Havazvidi, Seed Co Limited, Harare, Zimbabwe • Mohammad Reza Jalal Kamali, Director National Wheat Program, Iran • A.K. Joshi, Banaras Hindu University, Varanasi, India • R.A. Urazaliev, National Wheat Director, Kazakh National Academy of Science, • A.S. Absattarova, Head of Biotech Lab, Kazakh National Academy of Science • E. Duveiller, Wheat Pathologist, CIMMYT • R.J. Pena, Cereal Chemist, CIMMYT • K.D. Sayre and B. Govaerts, Wheat Agronomists, CIMMYT • J. Snape, Cereal Director, John Innes Centre, UK A wheat research priority-setting workshop was held with I. Trait and Germplasm Development representatives of 19 major wheat producing countries from II. Crop Management Sub-Saharan Africa (Ethiopia, Sudan, and Zimbabwe); III. Genotype-by-Environment Interaction South and Southeast Asia (Bangladesh, China, Nepal, IV. Biotic Factors India, and Pakistan*); Central and West Asia and Northern V. New Science Africa (Azerbaijan, Egypt, Iran,* Kazakhstan, Morocco VI. Quality Tajikistan, Uzbekistan, and Turkey); and Latin America VII. Policy/Socioeconomic Issues (Argentina, Brazil, and Mexico). 1 Collectively these VIII. Capacity and Information countries harvest 102 million hectares of wheat (47% of the global wheat area or 89% of the wheat area in developing I. Trait and Germplasm Development countries) and 285 million tons of wheat production (45% of Many of the ideas presented highlighted the perceived value the global wheat production or 92% of wheat production in of exploiting genetic diversity through wide crossing as well developing countries (FAO 2006). The remit of workshop as exploring the physiological potential of diverse sources of participants (who, in addition to the 19 country germplasm, especially with regards to stress adaptation but representatives, included wheat scientists from Australia, also to increasing yield potential; specific suggestions Canada, Czech Republic, France, Italy, Japan, Spain, included: • Broader introgression of genetic diversity introduced Sweden, United Kingdom, and United States of America, as well as CIMMYT and ICARDA; see the list of participants) through backcrossing with synthetic hexaploid wheat was to develop: developed by inter-specific hybridization of AB and D i) a list of priorities for future wheat research that could be genomes; this approach is favored as it has already best tackled in a globally-coordinated fashion; and provided significant impacts (Ogbonnaya et al., these ii) outlines of activities that would serve as templates for proceedings). • Raising the genetic yield potential of wheat using future project development for selected priorities. synthetic derived germplasm. • Making better use of translocation lines; to date only The need for a focus on priorities was brought into sharp relief by the evidence of declining investment in 1B/1R, 1A.1R, and 7DL.7Ag translocations have been international agricultural research (Pardey, these used systematically in breeding, but their benefits are well proceedings). The research areas suggested were grouped documented (see Foulkes et al., these proceedings). Many under the following sub-headings: more translocation lines have been produced, but few have been exploited by breeders since many translocations are in a Chinese Spring background (poor agronomic type) and/or have significant negative genetic linkage drag. 1 Drs John Dixon and Petr Kosina facilitated the workshop with the • Genetic vulnerability: better exploitation of existing assistance of Drs Mathew Reynolds and Tom Payne. genetic variability. Each year CIMMYT distributes over * Pakistan and Iranian country representatives were not present at the workshop but their ideas were represented through information collected in 1,000 new genetically diverse wheat genotypes targeted to the country surveys (see pages 54 & 79), also summarized by Kosina et al broad and diverse mega-environments through its (these proceedings), and through regionally based CIMMYT/ICARDA staff, international nursery system (Ammar et al.; Trethowan and they were also invited to review this document. 8
17. and Crossa, these proceedings). Identify mechanisms that leading to establishment of common mechanisms and, can be pursued for NARS to better utilize this pool of subsequently, identification of QTLs and candidate genes. • In the same vein, it was suggested that the extent to which diverse germplasm, for example, through promotion of wider testing or through farmer participation, to achieve yield has a common genetic basis across environments greater diversification of cultivars in farmers’ fields with widely varying yield levels be investigated; the QTL (Sharma et al.; Ortiz-Ferrara et al., these proceedings). approach is eminently well suited to addressing this issue, assuming suitable populations can be identified that are • Develop approaches for efficient allelic transfer from wide not confounded by agronomic traits. • The suggestion that research be organized around crosses. By employing relatively simple marker approaches (at least for re-synthesized wheat), the most physiological traits of known value would be valuable alleles or chromatic regions from the D or AB complementary to the approaches mentioned above. • It was also suggested that breeding programs should genomes can be identified to facilitate the process of transferring genes from these sources into modern develop and integrate selection environments to further hexaploid backgrounds (Kishii et al., William et al., these improve the resolution and heritability of trait expression. proceedings). • Improve durum wheat for marginal environments. Finally, there were questions relating to hybrid and perennial • Increased emphasis on targeted exchange of germplasm–– wheat: • What have we learned from hybrid wheat in terms of including segregating population at the F4–F6 levels–– between CIMMYT and NARS in relation to priorities at returns to investment? • Should we invest in breeding for perennial wheat, for the national level. example, in conservation agriculture (CA) systems? If so, A number of physiological traits were considered to merit investment in hybrid cultivars may result in the best urgent attention, including: economic return for farmers’ investments. • Lodging resistance in bread and durum wheat. • Drought tolerance, including root health; II. Crop Management • Heat tolerance, especially in light of clear evidence for Much of the discussion on crop management focused on strategic research in CA, which is starting to be widely global warming. Heat tolerance was also identified as the recognized as a foundation for sustainable agriculture; as trait with the highest priority for improvement in a survey having multiple benefits for farmers and the environment; sent to NARS scientists (Kosina et al. these proceedings) • Explore genetic diversity for rate of grain-filling (e.g., and as fostering sustainable economic development (see Chatrath et al.; Gupta and Sayre; Hobbs; Sayre et al., these from Chinese sources). • Implement stomatal aperture traits (such as canopy proceedings). An important and widely supported sentiment was the recognition that if farmers are using unsustainable temperature and stomatal conductance) as useful selection practices, sowing a modern variety will not solve the criteria for yield potential (Condon et al., van Ginkel et al., underlying problem––a corollary is that the full benefits of Brennan et al., these proceedings) genetic improvement will not be realized without sound crop • Increasing biomass and radiation use efficiency since management. This highlights the need to underpin partitioning may be approaching its upper limit (Fischer, investment in genetic technologies with complementary Foulkes et al., these proceedings). investment in both strategic and adaptive crop management • Understanding the physiological basis of high biomass in research so that investment in the former is adequately triticale and why its partitioning is relatively low. realized. This kind of research is becoming urgent because • Understanding the regulating mechanism for spike fertility resources for genetic improvement are increasingly being and grain set (for example, through embryo/kernel diverted from yield and quality improvement to maintaining abortion and sterility) to develop wheat backgrounds that the status quo (in terms of productivity) due to the need to are less sensitive to environmental fluxes during critical overcome problems associated with degraded soils (i.e., spike development stages; this could open new research micro-nutrient deficiency, incidence of soil-borne diseases, avenues to raise genetic yield potential (Reynolds et al., low soil organic matter leading to poor water capture and these proceedings). increased nitrogen losses) in both intensively and extensively cropped systems. Points were raised addressing research approaches, including the potential synergy of forming research consortia to tackle Successful CA systems are complex, adaptive systems that research issues such as those listed below: involve farmers, machinery manufacturers, extension, and • Our physiological knowledge might be reinforced using a input and produce marketers; the approach to research comparative biology approach whereby hypotheses about should incorporate adaptive learning of stakeholders in an adaptive traits could be tested simultaneously on different innovation systems framework (Dixon et al., these crop species. However, it was recommended that traits of proceedings). A coordinated, strategic science platform established value should be the initial research focus interacting with adaptive research hubs in various agro- 9
18. ecosystems is one effective model for such CA research. IV. Biotic Factors Topics that were highlighted for strategic research As expected, there were many concerns about biotic stresses included: since problems evolve as quickly as others are solved, as • Understanding the mitigating effects of CA on global highlighted by the rising threat of the stem rust race Ug99 in Eastern Africa. Collaborators highlighted the following warming through modeling its impact on: activities in relation to biotic stresses: (i) the carbon cycle and C sequestration • Greater networking with CIMMYT on disease screening (ii) the N cycle, soil microbiology, and greenhouse gas emissions nurseries and novel approaches to using doubled haploid (iii) physical fluxes at the soil surface, i.e., water, heat, technology; gene and genomic selection techniques for and dust particles (due to rainfall, radiation, and wind) and major disease resistance genes. • More work on rusts including screening and testing in rust their interaction with crop residues and soil cultivation. • The biological control of pests and diseases in CA systems. hot spots. • The impact of CA on system level water productivity. • The concept of durable resistance is accepted by many • Physiological and crop genome studies to identify traits wheat scientists, but its implementation is limited. Outside of CIMMYT, very few wheat breeding programs have and genes that maximize yield response under CA systems. • Adaptation of CA principles to all major agro-ecosystems based their breeding strategy on using minor genes as the basis for rust resistance. The concept of durable resistance (including reduced-till, bed planting, paddy rice should be applied by more programs. production, and cotton-wheat systems of Central/South • Assurance of durable rust resistance at high yield under Asia) recognizing the need to develop a coherent CA and other new RCTs. transition strategy that farmers can adopt without loss of • Assistance in identifying pathogen races. income. • Research in biological control of Sunni pest, root rots, and Other research areas in CA were highlighted, notably a set nematodes. • New diseases: wheat blast (Magnaporthe grisea), that could be considered more adaptive, as follows: • How to accelerate the adoption of CA in irrigated systems. currently reported from Brazil, Paraguay, and Bolivia, can • Local disease/pest/weed issues. result in zero yield). • Genotype x soil-tillage-residue interactions. • Crop residue for mulch versus biofuel issues. V. New Science There was a strong sentiment that investment in biotechnology must be made with the view to greater III. Genotype-by-Environment Interaction integration into breeding, as opposed to the isolation of new A far reaching suggestion was that, to enhance globally labs that has often been observed in wheat programs coordinated wheat research, the concept of mega- worldwide. There was discussion on how to influence the environments should be re-visited in a more dynamic way, research agenda so it will be problem-driven and not taking advantage of modern GIS capabilities (Hodson and technology-driven (e.g., the development of expensive White, these proceedings), as well as information from GxE markers for easily phenotyped traits). However, others analyses (Chapman et al., these proceedings) that did not highlighted that new does not just mean biotech and exist 20 years ago when the MEs were conceptualized emphasized the importance of CA in its potential to have (Braun et al., 1992). It was also suggested that breeding large impacts in agriculture. Specific suggestions for new targets should incorporate the evolution of new cropping research included: systems such as CA. New factors expected to be associated • Translational research: exploiting information from model with substantial GxE were listed: • Increasing biomass (as opposed to increasing harvest crop genomes such as Brachypodium and rice. • Research on genetically modified organisms (GMOs) to index) • Water scarcity identify new opportunities for disease/pest control. • Exploit the developing wheat sequence. • Global warming • Tillage systems VI. Quality Although quality has been a priority in wheat improvement Other suggestions in this area included the idea of for many decades, more specific quality characteristics that developing a common platform for data management in further facilitate market access and better satisfy consumer IWIS III (International Wheat Information Systems) at the demands are becoming substantially more important. In Cereal Research Information Laboratory (CRIL) at some instances, farmer income from wheat is reduced due to CIMMYT; incorporating more existing information into inferior grain quality. The following topics with reference to IWIS; and using models to help structure and better end-use quality were highlighted: understand G x E. • Biofortification and micro-nutrient enrichment are considered high priorities by some NARS. 10
19. • Market orientation and alternate uses (including the gain a better understanding of intensification and diversification pathways, and their interdependence. possibility of energy production). It was noted that increased demand could lead to decreased need for • Economics of trying to achieve higher yields. Real cost to subsidies to maintain farm income. • The effect of global climate change––increasing farmers? • What are the profit margins at different yield levels? temperatures/heat and increasing CO2––on quality (protein, • How will biofuel affect crop production in developing micro-nutrients). • High quality protein wheat was identified by some NARS countries, and should biofuels be a priority for developing as an important priority. countries? • Nutritional security and acceptable end-use quality. While VIII. Capacity and Information the former is currently of crucial importance for large It was generally recognized that opportunities for applied numbers of poor consumers mainly in rural areas, the training in plant breeding have been dramatically reduced. latter is growing continuously in importance, particularly Shortage of field wheat breeders has been already reported in urban areas. • The genetic/physiological/biochemical/chemical basis of from both developing and developed countries (Guimaraes et al., 2006; Morris et al., 2006; Baenziger, 2006; Kosina et different quality attributes needs to be better understood al., these proceedings). This trend is worrisome, particularly and addressed for the different types of food products. • Given the above priorities related to quality characteristics, for developing countries, and ways need to be found to address it. Discussed topics can be divided into three areas: economic research is required on the trends and analysis of G x E and wheat yield vs. quality in different markets. (1) Training courses in breeding, CA/agronomy, diseases and pests, industrial quality, and biotechnology. It is VII. Socioeconomic and Policy Research necessary to encourage the organization of training The following themes were identified as priorities: • Global food security remains a concern, as the world courses and raise donors’ interest. (2) Data and information management and knowledge population will increase by an extra 2.5 billion people by sharing. Scientific knowledge and dynamic networks 2050. Furthermore, millions of new consumers emerging are the key drivers of agricultural and rural development. from poverty are likely to increase demand for wheat There is an urgent need for intensive knowledge flow products. This requires an annual wheat production between advanced research institutions and NARS increase of 2%. One consequence is the need for more researchers. Valuable data, information, and knowledge visibility to promote extra funding of wheat research. held by advanced research institutions all around the • Improved projections and ex ante impact assessments: globe are, however, often fragmented. Access to data Where will the gains come from to meet global demand? and their interpretation through a common data-sharing Would higher value/quality wheat be more competitive platform (i.e., ICIS/CRIL) is requested by many NARS. than high yielding, lower quality wheat? It is necessary to To complement on-line access to data and information, reassess the trade-offs and relative importance between provision of specialized publications and facilitation of yield and quality as trade and market liberalization has visits for technology transfer has been requested from moved many countries from pursuing self-sufficiency to IARCs. competing in the international market. (3) Networks and collaboration. To address global • What are the conditions for rapid delivery of germplasm challenges in wheat breeding, formation of global and technologies along impact pathways and of their communities (based on traits, information, phenotyping, adaptation in local innovation systems? stress physiology, etc.) have been suggested. CIMMYT • A variety of networks and partnerships with NARS socio- and other IARCs should promote more collaboration economists would be beneficial if adequately funded,for with universities, while NARSs could strongly benefit they could take on common questions across wheat from joint breeding programs among themselves. producing countries. • The capacity of wheat seed systems to deliver quality seed Identifying Specific Research Themes in Priority Areas to small producers varies enormously––for example, in the The second half of the workshop involved identifying case of emergencies such as Ug99 rust. These systems specific research themes––those considered by the group to often lie at the interface of publicly funded research and be of most relevance in overcoming current constraints to commercial input providers. Identification of best wheat yield––within some key research areas (selected by practices for fast delivery of quality new varieties to small popular vote). The outcomes of these small ‘break-out’ farmers is a high priority. group discussions are presented below as a series of bullet • Participatory on-farm research is important to facilitate points representing potential collaborative projects, followed selection among new varieties and ensure adaptation of by some of the key comments raised in plenary presentations. improved agronomic practices. Moreover, diversification Where time allowed, brief concept notes were developed. will often be fostered by intensification. It is necessary to 11
20. • Assemble available genetic diversity locally (partner Use of physiological traits for pre-breeding and gene discovery countries) • Screen local wheat accessions with potential tolerance to The following themes were identified as top research priorities: heat and send best lines to CIMMYT for multiplication • Exploitation of comparative biology; taking information (n=50). Materials to be tested include: from major species and model species; focusing on traits o advanced lines and cultivars and genes for which there is strong evidence of impact on o products of inter-specific hybridization yield. o landraces • Determining common bases between abiotic stresses, such o (wheat alien species should be included in later phase) • Distribute international nursery to identify best parents for as tolerance to high temperature and drought. • Breeding for rapid grainfilling rate to improve adaptation crossing at CIMMYT • Develop crosses using data from all locations and to heat. • Increasing biomass by bringing together research progress complementary trait-based strategy, followed by selection in the areas of radiation use efficiency, spike fertility, in early generations to fix populations for resistance to partitioning, phenology, and signaling. rusts • Increasing the robustness of grain set, i.e., avoiding kernel • Distribute F4-F5 bulks to all partners for selection under abortion when environmental fluxes result in unfavorable local conditions • All partners will grow F6 derived yield trials weather during spike development. • Tailoring phenology to environments through deployment of Ppd, Vrn, and earliness per se (Eps). Partners: International centers, national wheat programs, • More comprehensive approach to breeding for lodging farmers where appropriate Capacity building: training and visits in breeding resistance. • Physiological and genetic characterization of parental methodologies including physiological trait evaluation, statistics lines used in crossing. • Deploying and integrating physiological screens for more Policy: What level of genetic improvement must be reached to target wheat-based systems as opposed to alternative effective early-generation selection. • Identifying performance QTLs that may be common crops Budget: $5 million across environments and gene pools for use in early- Timeframe: 5-10 years generation selection. Thrusts in strategic crop management research Methodologies to help actualize thrusts To help determine priorities, a matrix was made of • Use conceptual models to identify best candidate traits management options and the relevant biological disciplines, associated with yield improvement. i.e., Axis-1 included management factors: crop rotations and • Use targeted crosses to develop mapping populations that diversification, residue management, weed control, water will not generate progeny with a large range of management, tillage, and machinery. Axis-2 covered the confounding traits, while contrasting in trait(s) of interest. disciplinary areas: soil microbiology, nutrient fluxes, soil • Use association genetics when suitable RILs populations physical characteristics, and biotic and abiotic stress. Using are not identified and for gene discovery to identify that framework, the following areas of strategic research additive gene action. were identified as high priority: • Backcrossing to introgress more translocations into • Systematically investigate the ecology of disease and pest adapted backgrounds with little drag-on, e.g., 6AL, 7DL. spectra and their interactions with beneficial flora and fauna as they evolve in response to CA. Questions and answers • Quantify how CA practices (related to crop rotation, Q: On early-generation testing, do you have anything residue management, and fertilizer application) may particular in mind? increase nitrogen use efficiency and reduce trace gas A: Traits such as canopy temperature, leaf porosity, and emissions. spectral reflectance indices are ideal as they can all be • Establish basic principles on how crop rotations and measured within the same timeframe as visual residue and water management practices under CA observations are made, i.e., a few seconds/plot. optimize system level water productivity. • Determine the environments in which CA practices can Concept note: Develop Wheat with Improved Heat significantly ameliorate effects of a range of abiotic Tolerance stresses through improving root health and the soil’s buffering capacity in terms of nutrients and water Research design availability. • Develop conceptual models of traits for 2-3 major heat sub-environments 12