PHYSIOLOGICAL EVALUATION OF WHEAT GENOTYPES FOR LATE SEEDING WARMER CONDITION

Abstract

The present study was conducted at Crop Physiology and Ecology Laboratory and research field, Hajee Mohammad Danesh Science and Technology University (HSTU), Dinajpur during November, 2016 to April, 2017 to study on physiological evaluation of wheat genotypes for late seeding warmer condition. The experiment was laid out in split plot design with three replications. The main plot treatment consisted of three growing conditions- normal growing condition (November 20 sowing), moderate heat stress condition (December 20 sowing) and severe heat stress condition (January 10 sowing) and sub plot treatment consisted of four wheat genotypes (BARI Gom-26, BAW-1202, BAW-1182 and BARI Gom-27). BAW-1182 showed greater thermostability of cell membrane, greater flag leaf chlorophyll content, higher level of proline in flag leaf and kernel, greater ability to keep the canopy cooler and greater grain growth duration compared to BARI Gom-27, BAW-1202 and BARI Gom-26 under heat stress condition. BAW-1202 showed greater thermostability of cell membrane, greater ability to keep the canopy cooler and greater grain growth duration compared to BARI Gom-27 and BARI Gom-26 under heat stress condition. Better yield components such as tillers per m2 , spikes per m2 and grains per spike under heat stress condition contributed to better tolerance of BAW-1182 and BAW-1202. The order of tolerance based on heat susceptibility index (based on grain yield) was BAW-1182 > BAW-1202 > BARI Gom27 > BARI Gom-26 under moderate and severe stress conditions.