Measures of Genotype Wide Adaptation Level and their Relationships in Winter Wheat

Three new concepts of genotype wide adaptation levels I, II and III are presented and shown to the adequate describing quantitatively by measures such as superiority measure, P-i, Eskridge's yield reliability measure, R-i and Eskridge's yield reliability function, R-i(d). These indices have been called quantitative measures of genotype wide adaptation levels I, II and III, respectively. Relationships (consistency) between the three measures were studied using data for grain yield of winter wheat advanced lines from 15 preliminary multi-environment trials carried out across Polish test locations in the years 1993-2007. The quantitative measures are simple to interpret and useful quantitative characteristics of genotype wide adaptation levels I, II and III. High Spearman rank correlation coefficients were found between each of the pairs of the quantitative measures of genotype wide adaptation levels I, II and III within all sets of winter wheat genotypes. Then, for evaluating wheat genotype wide adaptation level in each aspect only one of the considered measures could be sufficient. The studies delivered new results on the usefulness of quantitative measures of genotype wide adaptation level for winter wheat. These findings indicate that those measures could be also useful for comparative evaluation of genotype wide adaptation level in other crops.