PJB-2019-556
MORPHO-MOLECULAR SCREENING OF WHEAT GENOTYPES FOR HEAT TOLERANCE
Nihar Ranjan Saha
Abstract
Heat stress is a threat to agricultural productivity especially wheat (Triticum aestivum L.). Wheat production during Rabi season in Bangladesh is often impaired by heat stress. Therefore, it has been a priority to develop heat tolerant wheat variety for Bangladesh. The present investigation was carried out with an aim to evaluate locally cultivated wheat genotypes for heat tolerance based on morpho-physiological and molecular markers. A pot experiment was carried out with ten locally cultivated wheat genotypes grown under control and heat treatment conditions. Heat treatment was imposed 5 days after anthesis conducted in a plant growth chamber at 35 ºC and 70% RH for 3 days. The heat stress affected all the yield contributing characters and ultimately led to a reduction in grain yield. Significant variations were observed for all morphological and physiological traits. Susceptibility index and tolerance efficiency were used as criteria for selection of heat tolerance. The BARI gom-29, BARI gom-30 and BARI gom-28 emerged as heat tolerant variety. BARI gom-25, BARI gom-20 and BARI gom-22 were found to be moderately tolerant. On the contrary, Shatabdi, BARI gom-23, BARI gom-26 and BARI gom-24 were heat susceptible. Twenty six wheat genotypes were screened for heat tolerance through seven linked SSR markers. A total of 44 alleles were detected among the 26 wheat genotypes with an average of 6.28 alleles per locus for heat related SSR markers. Overall polymorphism information content (PIC) and Nei’s (1973) gene diversity were detected to be 0.68 and 0.72, respectively. Similarity indices based UPGMA analysis separated 26 genotypes into different clusters. In which, two morphologically identified tolerant genotypes namely BARI gom-29 and BARI gom-30 and one moderate genotype BARI gom-22 were grouped in cluster 2. Therefore, these three varieties can be suitable for cultivation in the north-western part of Bangladesh as heat tolerant cultivars.
To Cite this article:
Download
