Study on stability of grain yield and harvest index in promising bread wheat lines in cold regions of Iran

Genetic and environmental factors can affect the performance of the genotypes. Genotype ×environment interaction could be result different reaction of the genotypes in different environments. Therefore، determination of stability of the genotypes in different environments is the most important. In this study 15 winter and facultative bread wheat genotypes (including two check cultivars) were used. This experiment was conducted in 11 research stations in cold regions in 2003-04 and 2004-05 cropping seasons. Experiments design was randomized complete block (RBCD) with three replications. Based on results of combined analysis of variance، effect of year، location، genotype and genotype × year interaction effects were found non-significant. However، location ×year، genotype ×location and، genotype × location ×year interaction effects were significant. Based on stability parametric methods such as coefficient of variability (CVi%)، Shukla stability variance (σi2)، simultaneous selection for yield and stability (YS)، and non-parametric method of ranking genotype C-82-12 (Fdl4/Kauz) with average grain yield of 7035 kg ha-1،YS=18، R=5. 86، SDR=3. 427non-significant stability variance (σi2) and low environmental CV was identified as high yielding and stable genotype.