EFFECTIVE APPLICATION OF CANOPY TEMPERATURE FOR WHEAT GENOTYPES SCREENING UNDER DIFFERENT WATER AVAILABILITY IN WARM ENVIRONMENTS

High temperature and drought are the most important abiotic stress factors which influence the wheat production in major parts of the wheat grown areas in Iran. This study was conducted to identify the proper criteria (morphological or physiological markers) for screening the heat and drought tolerant wheat genotypes under field conditions as well as to find out the sources of terminal heat and drought tolerance for utilization in the breeding programs. Under dryland, supplemental and full irrigation (exposed to high temperatures after anthesis), nine bread wheat genotypes were evaluated in three separate experiments at Gachsaran agricultural research station which is located in southwest of Iran in 2010-2011. This study showed the strong association between yield and canopy temperature under different intensity of drought (*P <0.05, and **P <0.01 under dryland and supplemental irrigation conditions respectively), and heat (**P < 0.01) stresses, indicating the trait potential as an indirect selected criterion for achieving genetic gains in heat and drought adaptation. It was concluded that the combined heat and drought stresses, considerably, reduced grain yield more than by either stress alone, but not with additive effects. Some genotypes, in particular, genotype 7 (T.AEST/SPRW'S'//CA8055/3/ BACANORA86) was identified as low CT value and high grain yield in all environments. This genotype was released through Agricultural Research, Education and Extension Organization (AREO) under the name of "Karim" in Iran in 2011.