DWAP 1531: An early maturing bold seeded bread wheat germplasm for warmer areas

Abstract

The wheat growing areas in the country has been divided into five mega zones and the wheat crop in four zones namely, North Western Plains Zone (NWPZ), North Eastern Plains Zone (NEPZ), Central Zone (CZ) and Peninsular Zone (PZ) experiences warmer climatic conditions during grain growth period. The wheat production is adversely affected in these areas as grain yield and its components were reported as a function of variable responses of different genotypes to heat in different stages of wheat development (Lillemo et al., 2005; Yildirim and Bahar, 2010). Grain mass is the most important character to confer heat tolerance (Reynolds et al. , 1994) but the variation among genotypes for grain yield under heat stress is due to a larger variation in number of spikelets per spike and number of grains (Shpiler and Blum, 1986). Lower grain yields were reported due to susceptibility of the genotype to heat during the grain filling stage as demonstrated by the reduction percentage in 1000-grains weight (Pimental et al., 2015). The effect of warmer climatic conditions on grain yield due to reduction in grain number and 1000-grains weight was also reported by Modarressi et al. (2010). Therefore, these traits along with spike length, were appointed by Farooq et al. (2011) as essential for selection of heat tolerant genotypes. Keeping these in view, it was felt that there is need to develop early maturing genotypes that can avoid warmer temperatures and, proper grain filling in these genotypes resulting in bolder seeds to sustain the adverse climatic conditions. Research efforts were made to combine adaptability traits into high yielding wheat varieties in order to get improved germplasm adapted to warmer areas. A large number of germplasm lines have been developed in the warmer area programme of the IIWBR, Karnal and being contributed in national nurseries for multi-location evaluation and sharing with cooperating centres. During 2015-16, a total of 12 wheat genotypes, developed in warmer area programme, were contributed in Yield Component Screening Nursery (YCSN). Among these, the germplasm line DWAP 1531 has been found promising for early heading and maturity possessing bolder seeds.