Abstract

The experiment was conducted during winter 2010 and 2011 to assess heat tolerance of 17 genotypes under four environments (two sowing dates with two years). The combined analysis of variance showed that the differences between genotypes as well as GXE were highly significant for grain yield, 1000 grain weight, number of kernel/spike and spike length. The genotypes No. 1, 2, 3 and 7 gave high mean grain yield, regression coefficient "b" not significantly from unit and considered more stable. Meanwhile, genotypes No. 1, 2, 4, 15 and Giza-168 showed below average stability (b=1.92, 1.72, 2.24 and 1.6). Also, genotypes No. 1, 2, 3 and 7 were relatively heat resistance (HSI values <1), while local variety Giza-168, Sids-12 genotypes No. 13, 14 and 12 were relatively susceptible to heat stress. In general, in drought environments, grain yield of genotypes No. 1, 2 and 3 were the highest.

Key words: Environment, genotype, genotype by environment interaction, grain yield, heat stress.