Gene Bank to Farmers' Field: Accessing Genetic Diversity for Biofortification Breeding in Wheat.

Gene bank to farmers’ field: accessing genetic diversity for biofortification breeding in wheat Govindan Velu1, L. Crespo-Hererra1, Julio Huerta1, Tom Payne1, Bibiana Espinosa1, James Stangoulis2 and Ravi P. Singh1 1 International Maize and Wheat Improvement Center (CIMMYT), Mexico 2 School of Biological Sciences, Flinders University, Adelaide, Australia Corresponding author email: velu@cgiar.org Breeding wheat with enhanced levels of grain zinc (Zn) and iron (Fe) provides a cost-effective, sustainable solution to the malnutrition problems in the developing world. Modern wheat varieties have limited variation for grain Zn and Fe, hence a large scale screening of wheat genetic resources at CIMMYT was initiated to explore variation for Zn and Fe amongst the wild relatives. Einkorn wheat, wild emmer wheat (T. dicoccoides) and diploid progenitors of hexaploid wheat such as Ae. tauschii, T. monococcum and T. boeticum and landraces, were the most promising sources for high grain Fe and Zn concentration, followed by T. spelta, and T. polonicum. A recent field evaluation of a set of Mexican and Iranian landraces (conserved at the CIMMYT gene bank) screened under Zn-enriched soil conditions at Cd. Obregon, Mexico showed that there was more than 2-fold variation for grain Zn (40-96 mg/kg) and Fe (27-56 mg/kg). The available genetic variation from different species and landraces was used in the biofortification breeding program to develop nutrient-enriched wheat germplasm. A more recent success was the development and deployment of a Zn-enriched wheat variety, ‘Zinc Shakti (Chitra)’ adopted by more than 250,000 farmers in India and this was developed from the introgression of a synthetic hexaploid (Ae. squarrosa) progenitor crossed into elite germplasm. The ‘Zinc Shakti’ variety has 40% higher grain Zn with profitable yield potential and matures nearly two to three weeks earlier than the non-biofortified wheat grown in the target regions of South Asia.