Genotypic difference for heat tolerance traits under real field conditions
Published on Jan 1, 2012
The difficulty of selecting for improved adaptation to heat stress makes the use of indirect measures attractive to plant breeders. To examine the response to selection on canopy temperature, leaf chlorophyll content, Fv/Fm ratio and kernel weight and to evaluate the response of some wheat genotypes facing high temperatures during and after anthesis under field conditions, ten bread wheat genotypes were exposed to two different sowing dates: normal and late sowing, to assure high temperatures during and after anthesis, in 2010-2011 in a field adjacent to Gachsaran Agricultural Research Station that is located in southwest Iran. Results indicated significant difference for all physiological traits and significant phenotypic correlation with grain yield, particularly in more heated environments. Canopy temperature explained 71 and 54.2% of grain yield variation in more and less heated environments, respectively. The lines having tolerance to high temperature during grain filling stage were marked for future breeding program.