Journal of Crop Breeding

In order to decrease effect of genotype × environment interaction, yield and yield stability should be considered simultaneously. In present study, 24 bread wheat genotypes were evaluated in Gorgan and Gonbad agricultural stations in 2012-13 and 2013-14 cropping seasons. Experiments were conducted based on complete block designs with three replications at 6^th December and February. Combined analyses of variance confirmed that the effects of year, location, genotype, year × genotype, location × genotype and year × location × genotype interactions were statistically significant (P<0.99). For determining stable genotypes, non parametric and simultaneous selection of yield and yield stability (Ys_i) methods were used. Based on NP_i⁽¹⁾، NP_i⁽²⁾، NP_i⁽³⁾ and NP_i⁽⁴⁾ non parametric methods genotypes 2, 9, 24 were selected as high yielding and the most stable genotypes. These genotypes had less than grain yield mean. Results of  S_i⁽¹⁾, S_i⁽²⁾ methods showed that genotypes 9 and 17 had the highest stability, while genotypes2 and 8 were also stable genotype in S_i⁽³⁾ and S_i⁽⁶⁾ methods. According to simultaneous selection for yield and yield stability (Ys_i) genotypes 22, 14, 20 and 19 were determined as stable genotypes. These genotypes had grain yield more than grand mean yield. Simultaneous selection for yield and yield stability (Ys_i) method selected genotypes with high grain yield and high stability. Finally, results of stability analyses revealed that genotype 22 with mean grain yield of 3932 kg.ha^-1 was the most stable genotype.