Marker assisted selection: a strategy for wheat improvement Bhakti Rana1, Preeti Rana 2, Manoj K. Yadav1, Sundeep Kumar1

Challenges and future strategies in India
India’s population of more than a billion is growing at a rate of around 1.8% per year, almost going parallel with the annual growth rat of cereals. Therefore, the estimated demand of wheat production for the year 2020 is around 109 million tones, which is 30 million tones more than the record production of 75 million tones harvested in the crop season 1999-2000. Since then, India is struggling to achieve the impressive figure of its record production. However, the ever increasing population has alarmed food security in India and attempts have been initiated to integrate modern technology tools in conventional breeding to improve the most important crops such as rice, wheat and legumes. There is little doubt that wheat has been a difficult species for the application of molecular genetics. The low level of polymorphism between elite varieties coupled with the hexaploid nature of the crop provides significant challenges for those attempting to develop molecular markers and to use them in genetic studies. With the development of AFLP and microsatellite marker systems, renewed studies are underway to analyze the genetic basis of many important traits in wheat. Future challenges include developing strategies for reducing the cost per assay, acquire more desirable markers to further complement the efforts of wheat breeders as well as evaluating emerging technologies to increase throughput with reduced cost. Integrating molecular breeding efforts in a few target national program partners also is considered an important challenge. One of the major concerns of wheat researchers is to make Indian wheat globally competitive by reducing the cost of cultivation and increasing farmer’s profitability. With the availability of detailed information regarding the location and function of gene(s) encoding for useful traits, scientists in future will be well equipped for efficiently creating varieties with exact combinations of desirable traits. However, genetic transformation will remain a significantly important tool for understanding gene functions and for testing the utility of new sequences. In near future, crop varieties could be tailor-made to meet both local consumer preferences and the demands of particular environment or niche. CIMMYT, Mexico has played an important role in strengthening the Indian wheat programme since the advent of Green Revolution. In light of the fresh challenges CIMMYT is giving emphasis on molecular breeding, functional genomics, deployment of transgenes for abiotic stresses etc., should get priority to maintain pace with time and growth. In near future, molecular markers can provide simultaneous and sequential selection of agronomically important genes in wheat breeding programs allowing screening for several agronomically important traits at early stages and effectively replace time consuming bioassays in early generation screens. Although, the potential of biotechnology has often been exaggerated, a high level of optimism is clearly justified for its use in the improvement of wheat. Undoubtedly, functional genomics, as it is now termed, will revolutionize the way in which plant breeding is undertaken in the future. Basic research is leading to an improved understanding of the genetic mechanisms operating within a plant in response to the diverse stresses that it is exposed to, as well as the overall production of biomass and grain. The challenge for developing countries is to tap as much of this emerging technology as possible.