Relationships of phenotypic stability measures for genotypes of three cereal crops

Abstract

Mohammadi, R., Roostaei, M., Ansari, Aghaee, M. and Amri, M. 2010. Relationships of phenotypic stability measures for genotypes of three cereal crops. Can. J. Plant Sci. 90: 819-830. Multi-environment trial (MET) data are required to obtain stability performance parameters as selection tools for effective genotype evaluation. The main objective of this study was to investigate the interrelationships among nine phenotypic stability methods using grain yield from three sets of cereal experiments [15 durum wheat (Triticum turgidum var. durum) genotypes x 12 environments; 20 bread wheat (T. aestivum L.) genotypes x 18 environments; and 13 barley (Hordeum vulgare L.) genotypes x 18 environments]. The experiments were conducted in representative rain-fed areas of Iran in collaboration with the International Center for Agricultural Research in the Dry Areas (ICARDA). The combined ANOVA for environments (E), genotypes (G) and G x E interaction was highly significant (P <0.01) for each set of data, suggesting differential genotypic responses and the need for stability analysis. The inter-relationships among the parameters and their association with mean yield based on Spearman's rank correlation were determined in each of the three cereal experiments. Highly significant correlations were found between several of the stability measures indicating that several of the statistics probably measure similar aspects of phenotypic stability for these crop species. The AMMI stability value (ASV), variance of regression deviation (S-di(2)) and Wricke's ecovalence (W-i(2)) were consistently and highly correlated with each other over these crops and, therefore, could be used if selection is to be based primarily on stability. The superiority index (Pi) and geometric adaptability index (GAI), which are related to the dynamic concept of stability showed significant correlation with mean yield over these crops, suggesting P-i and GAI would be the best methods for ranking genotypes across environments. The coefficient of variation (CV), regression coefficient (b(i)), yield reliability index (l(i)), and environmental variance (S-x(2)) showed inconsistent relationships with either the static or dynamic concepts of stability over these crops. The correlation analysis provided a good description of static and dynamic concepts of stability for interpreting the G x E interaction and verified that the groups of stability methods (dynamic vs. static) discriminated genotypes in different fashions in these crops.