Validation of SSR Markers Linked with Drought and Heat Tolerant QTLs in Bread Wheat (Triticum aestivum L. em.Thell.)

Abstract

Global warming caused by enhanced CO2 in the atmosphere could disturb agriculture in future and lead to water deficit. Drought and heat stress is presently a major limitation to wheat productivity in arid, semiarid, tropical, and subtropical areas of the world. Marker-assisted selection which holds promise in improving selection efficiency and expediting the development of new cultivars with higher grain yield potential is used as a selection criterion for the development of stress tolerant varieties. Validation and use of markers linked with drought and heat tolerance traits that are previously reported across different populations would enhance the selection efficiency of MAS. In the present study, crosses were made between recipient parent HD2733 with two different donor parents HI1500 and WH730. In the BC1F2 population developed from the two crosses, different SSR markers viz., barc68-barc101, gdm93, gwm165 linked with drought tolerance QTLs, (chlorophyll content and canopy temperature), (normalized difference vegetation index), (grain yield) respectively and barc186, gwm190 linked with heat tolerance QTLs,(days to anthesis), (grain yield) respectively, were validated for their use in marker assisted selection (MAS) in BC1F2 segregating generation derived from cross HD2733X HI1500 (drought tolerance), HD2733X WH730 (heat tolerance). Both the markers gwm165 and gwm190 were linked with grain yield per plant in derived backcross populations. The six SSR markers were found appropriate for selection of drought and heat tolerant segregating lines in marker assisted backcross breeding (MAB) programs.