BREEDING ADVANCES IN DEVELOPMENT OF BIOFORTIFIED WHEAT CULTIVARS G. Velu, R.P. Singh and Y. Hao International Maize and Wheat Improvement Center (CIMMYT), Apdo. Postal 6-641, 06600, Mexico DF, Mexico Corresponding email: email@example.com
Dietary deficiency of essential micronutrients such as zinc (Zn) and iron (Fe) in human is very common, especially in countries with high consumptions of cereal-based diet. Genetic biofortification to improve Zn and Fe in bread wheat could greatly reduce micronutrient malnutrition worldwide. Wheat (Triticum aestivum L.) is the second most produced cereal crop, contributes 28% of the worlds dietary energy in many parts of the world. Therefore, there is a great need to improve nutritional value of wheat grain along with other essential core traits. Currently, the International Maize and Wheat Improvement Center (CIMMYT) is working to develop and disseminate high-yielding, rust-resistant wheat varieties with significantly increased Zn and Fe concentrations in preferred end-user types. It is expected that adoption of high Zn wheat varieties will be driven by its improved agronomic properties compared to current popular varieties, and breeding has focused on both Zn content and resistance to new strains of yellow and stem rusts. A targeted breeding program was initiated at CIMMYT in 2006 to develop wheat varieties that has 8 parts per million (ppm) increased Zn over the popular varieties (25 ppm) with competitive yields and resistant to rusts including Ug99 races of stem rust. Current breeding efforts at CIMMYT have focused on transferring genes for increased Zn from T. spelta and T. dicoccon based synthetics, landraces and other reported high Zn sources to high yielding elite wheat backgrounds. The first proof of concept results from the CIMMYT-derived high Zn lines tested at target environments showed high heritability along with high genetic correlations between locations, and a considerable number of entries exceeded the intermediate to full target level of Zn in trials across diverse environments suggests feasibility of developing competitive biofortified varieties with farmer- and consumer-preferred agronomic and end-use traits. Candidate lines identified with more than 75% of the Zn target level with better resistance to rusts are being tested in large scale multi-location trials in India and Pakistan and the first release of biofortified wheat is expected in India by 2014-15.