ASSESSMENT OF HEAT TOLERANCE IN WHEAT (TRITICUMAESTIVUM L.) AT THE SEEDLING STAGE

Wheat (Triticum aestivum L.) is a primary food crop globally, susceptible to environmental fluctuations, particularly the heat stress. With climate change and its increasing threats, wheat's response evaluation to the elevated temperatures during early growth stages is crucial for securing the crop and its yield. The presented study sought to assess the heat tolerance in 15 common wheat cultivars at the seedling stage under controlled conditions. Growing wheat cultivars ensued at the optimal (25 degrees C) and heat-stressed (35 degrees C) conditions. After seven days of growth, the seedling height, root length, and root number's measurement underwent assessment for heat stress effects. The quantification of the degree of plants damaged used the Damage Index (DI), with heat tolerance evaluated using the Heat Tolerance Index (HTI). The results showed significant variations among the wheat cultivars for heat tolerance, and the two cultivars, Tuyatish and Nodir, displayed minimal growth reduction under the highest temperature, achieving maximum HTI values (98.3% and 89.6%, respectively). The cultivar FAWWON-IRR-D-77 exhibited a substantial damage and low tolerance under high-temperature stress. This study provides essential insights into heat tolerance mechanisms in wheat, forming a foundation for future breeding and molecular studies aimed at improving heat resilience in crops.