Evaluation of some wheat genotypes growing under heat stress condition in two environments in Bangladesh

The study was carried out from November to March, 2013-2014 in two agricultural research centers/stations: Wheat Research Centre (WRC; 23° 11' 14.52" N, 89° 11' 11.99" E; 10.4 meter above sea level, masl), Nashipur, Dinajpur and Regional Agricultural Research Station (RARS), Jashore (23° 11' 14.52" N, 89° 11' 11.99" E; 10.4 masl) of the Bangladesh Agricultural Research Institute (BARI). Sixteen genotypes along with two check varieties BARI Gom 21 and BARI Gom 26 were evaluated in Randomized Complete Block Design (RCBD) with three replications under irrigated timely sown (ITS) and irrigated late sown heat stress (ILS) conditions to find out the heat-tolerant wheat lines for future breeding program to develop heat-tolerant wheat varieties. Significant variations were observed among tested genotypes on phenology, yield and yield contributing characters at late sown heat stress condition (ILS) in both locations. The higher yield across location and genotype was recorded in ITS condition (4224 kg ha-1) than ILS condition (3113 kg ha-1). Regarding environmental locations, Dinajpur was better placed for wheat production. Among the tested genotypes, Gen-3, gen-8, Gen-10, Gen-11, and Gen-16 showed better performance under ILS condition and these genotypes were selected for the future breeding programs to develop heat-tolerant varieties. The selected genotypes had high yield, bold and plump grains with better tolerance to Bipolaris leaf blight (BpLB) and resistance to leaf rust diseases.