Study on adaptation and stability of grain yield in bread wheat genotypes in uniform regional yield trials in cold and temperate dryland areas.

Breeding cultivars of wheat with higher adaptablility, yiled stablility and grain production is imortant for cold and temprate dryland regions. Hence, this research was coducted in order to evaluation of adaptability and stability of 14 advance lines and Azar2 and Sardari varieties(checks) in Dryland agricultuir research stations of Maragheh, Gamloo, Sararood, Zanjan, Shirvan, Uruomieh and Ardabil in 2006 to 2009 years in randomized completely block design (16 genotypes × 4 replicates × 7 locations × 3 years) under rainfed condition. Data was collected from desirable characteristics like days to heading, days to physiologic maturity, plant high, 1000- kernels weight, cold tolerance, resistance to lodge and shattering, plant disease like carnal bunt, yellow rust, leaf rust and grain yield dureing seasenal plant growth. Simple analysis of variance of grain yield was done for each experiment separately and homogeneity test of errors variance was calculated using F max hartly test. Errore variance of secend year of Uromiyeh's trial was very small and this trial was not used in yearly combined analysis of this station.The combined analysis was done for 17 envirnoments and its result indicated that main effect of genotype and envirnoment and interactions of envirnoment ×genotype were significant. Hence, three stability parameters were used to determine stable lines, including environmental coefficient of variation (C.Vi) and Mean Square of years within location for a genotype (MSy/l), and ranking method. Stability analysis results showed that genotyps has not wide adaptability, therfore selection of genotyps was done based on specific adaptability. Based on stability parameters, agronomy triats of genotyps and climatic charactristics of stations, line 13 in Maragheh, lines 3 and 11 in Ardabil, line 3 in Zanjan and line 10 in Uromieh and Sararood was selected for on-farm trial and variaty intrduce program. In Gamloo station no line was not supriore than Azar2.