Enhancing Yield Potential of Hard Red Winter Wheat Via Use of Synthetic Backcrosses.

Wheat (Triticum aestivum L.) is one of the major staple food crops around the world with the annual production of 650 million tons. With increase in global population, the demand for wheat is expected to reach 900 million tons by 2020. However, narrow genetic base and continued pressure from abiotic (drought, heat, frost) and biotic (pest, disease) stresses pose a tough challenge to achieve expected increase in grain yield. Research leading to evolution of synthetic hexaploid wheat (Triticum durum X Aegilops Tauschii) and populations (synthetic derivatives) generated from crossing synthetics with adapted elite cultivars present tremendous opportunities to improve wheat production. The Wheat Breeding Program of Texas AgriLife Research have developed synthetic derived population using crosses between synthetics from the International Maize and Wheat Improvement Center (CIMMYT) and elite hard red winter (HRW) wheat cultivars ‘TAM 111’ and ‘TAM 112’. Preliminary studies on the synthetic derived population showed promising lines with increased seeds per head, grain yield, and seed weight, and better resistance to disease and pest incidences. Seed weight trait has been found to be highly heritable in these synthetic derivatives. Hence, we hypothesized that by optimizing and selecting for traits such as number of head per unit area and seeds per head, it is possible to increase yield in spite of inter-component compensatory effect. Accordingly, our objectives for this study are to a) characterize synthetic derived populations, derive lines, and predict gain in grain yield via indirect selection for yield components, b) conduct association mapping to identify unique alleles for drought and heat tolerance, c) determine the allelic relationship between greenbug resistance present in some of the synthetic lines by comparing with Gb3 gene in TAM 112. The long-term goal of this project is to enhance yield, as well as biotic and abiotic stress tolerance of HRW.