To study the stability and adaptability of grain yield in advanced genotypes of bread wheat in warm and semi-warm dryland areas, 24 advanced genotypes were evaluated in Gachsaran, Koohdasht (Lorestan), Moghan and Gorgan Experimental Stations during 1998 - 2001 cropping seasons. The experimental design for all locations was a Randomized Complete Block one (RCB) with four replications. In each location simple as well as combined analysis of variance were carried out. Results showed significant difference among genotypes in most locations as well as years. Because of homogenity of error variances being insignificant, combined analysis of variance was done for locations as well as for years. Results showed that interaction of genotype x year x location was significant at 1% probability. A significant difference was also found among genotypes, with genotypes no.4 (Tr8010200) and 15 (Tan”s”/Pew”s”) yielding 2635 and 2550 kgha’ of grain respectively, producing the highest yield. Zagros (the control cultivar) produced 2462 kgha’ of grain as yield. Results of statistical analysis on grain yield, using parametric method of C.V.% and Lin & Binns, as well as non- parametric method of Rank indicated that no.4 (Tr8010200) was the most stable genotype. Based on the obtained results genotype no.4 (Tr8010200) was found to be the highest in yield as well as in stability and therefore was released as variety Koohdasht for Warm and Semi-Warm dryland areas.
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