Evaluation of Wheat Genotypes for Heat Tolerance

Abstract

Two experiments were conducted at the Dr. Purnendu Gain Field Laboratory and Plant Breeding Laboratory of Agrotechnology Discipline, Khulna University, Khulna during the period from 04 December, 2016 to 23 March, 2017 to identify wheat genotypes for heat tolerance. Eleven wheat genotypes viz., BARI gom-20 (Gourab), BARI gom-21(Shatabdi), BARI gom-22 (Sufi), BARI gom-23 (Bijoy), BARI gom-24 (Prodip), BARI gom-25, BARI gom-26, BARI gom-27, BARI gom-29, BARI gom-30 and Sourov were used as the study materials. The genotypes were evaluated in randomized complete block design (RCBD) and complete randomized design (CRD) with three replications. A simple analysis of variance was performed on plant height, number of leaves/plant, tillers number/plant, number of grains/spike, total grain weight, 1000 grain weight, straw weight and harvest index. To evaluate the sensitivity or tolerance level of the genotypes to heat stress, five indices namely stress susceptibility index (SSI), stress tolerance index (STI), geometric mean to product (GMP), tolerance index (TOL) and membrane stability index (MSI) were studied. The response of BARI gom-20 (Gourab), BARI gom-21 (Shatabdi), BARI gom-24 (Prodip) and BARI gom-26 were better in terms of tolerance index (STD, geometric mean to product (GMP), tolerance index (TOL), membrane stability index (MSI) and grain yield both under stress and non-stress condition. Therefore BARI gom-30 showed the lowest stress tolerance index (STI), geometric mean to product (GNP), tolerance index (TOL), membrane stability index (MM) and grain yield. so, BARI gom-24 (Prodip), BARI gom-21(Shatabdi), BARI gom-20 (Gourab) and BAPd gom-26 were considered as heat tolerant. Among the eleven genotypes BARI gom-30 showed the lowest performance and was considered as a heat susceptible genotype.