Evaluation of Genotype × Environment Interactions, Stability and a number of Genetic Parameters in Rice Genotypes

In order to investigate yield stability, genotype×environment interactions and estimation of a number of genetic parameters related to yield and yield components, seven promising rice lines together with Shirodi and line 843 (as control cultivars) were evaluated. The experiment was carried out base on randomized complete block design with three replications in three locations of Mazandaran province, Iran (Tonekabon, Amol and Sari) during three growing seasons from 2012 to 2014. Analysis of variance revealed that there were significant differences among genotypes for yield at almost all three locations. Combined analysis of variance indicated that there were no significant differences among locations and years, whereas year×location×genotype interaction was found significant for grain yield, plant height and thousand grain weight. Results of stability analysis by univariate methods showed that genotype number 6 was the most stable genotype over all three locations, having less variance within locations and smaller coefficients of variance and a high grain yield (6020.8 kg ha-1). The high coefficient of phenotypic and genotypic variation was indicative to genetic variability for all of the studied traits. The broad-sense heritability ranged from 49.06% (plant height) to 92.48%% (number of filled grain per panicle) and was 59.46% for grain yield. The highest phenotypic and genotypic coefficients of variation and genetic gain over total average obtained for the number of grains per panicle. Thus, it is possible to improve this trait by selection method and could be used as a selection index to improve grain yield. Overall, genotype number 6 could be considered as a superior genotype to achieve a dwarf cultivar with stable yield.