A Consideration on Genotype and Environment Interactions and Stability of Grain Yield in Promising Lines of Rice (Oryza sativa L.)

In order to determine the genotype × environment (GE) interactions and yield stability, an experiment was conducted with 10 promising genotypes of rice and two control varieties (Shiroudi and Fajr) in four regions of Mazandaran (Amol , Babol, Sari and Tonkabon) using randomized complete blocks design with four replications during two cropping seasons (2012-2013). Analysis of variance showed significant differences for grain yield among genotypes. Combined ANOVA was also performed following Bartlett uniformity test (for uniformity of error variances). Results showed significant differences among the genotypes. Non-significant effects observed for location. year and genotype × location and genotype × year interactions means that the genotypes had similar response over different locations and years. Stability of genotypes were evaluated using seven different methods including: the variance and coefficient of environmental variability, Wricke’s equivalence, Shukla’s stability variance, coefficient of regression, the variance of deviation from regression, within location variance. Results showed that genotype No.4 and control variety Fajr, were determined as stable genotypes, because of low S2i, CVi, MSy/p, Qi2 and Wi2 and bi equal to unity and non- significant S2di.