Assessment of wheat (Triticum aestivum L.) genotypes for high temperature stress tolerance using physico-chemical analysis

摘要

High temperature stress would be one of the major threats to wheat productivity due to changing climate scenario. A field study was carried out at Experimental Farm of Nuclear Institute of Agriculture, Tando Jam during 2014-15 by using 20 wheat genotypes (mutants and advance lines) along with four check varieties Sarsabz, TJ-83, TD-1 and Kiran-95. The breeding material was subjected to two different sowing dates viz. sowing date-1 (November 15 as normal sowing) and sowing date-2 (December 25 as late sowing to induce high temperature stress at grain filling). Along with agronomic, breeding data, physiological parameters i.e., SPAD chlorophyll content, proline, osmotic potential and leaf area were assessed in both normal sown and late sown crop to see the affect of high temperature stress at different traits including physico chemical parameters. Results revealed that seven genotypes NIA-8/7, NIA-AMBER, BWS-78, NIA-10/8, NIA-28/4, DH-12/1 and check KIRAN-95 were found tolerant to heat stress and produced higher grain yields ( 4000 kg ha -1 ) under heat stress conditions. While out of seven genotypes, five genotypes DH-12/1, BWS-78, NIA-10/8, NIA-28/4, and Kiran-95 possess one or the other efficient physiological mechanism to cope with heat stress. Whereas NIA-8/7 and NIA-Amber were found having superiority in agro-morphological traits under stress conditions. Most of the physiological traits SPAD chlorophyll and leaf area, proline and osmotic potential had no any significant correlation with grain yield in normal sown crop and highly significant correlation of these traits were calculated under heat stress conditions.