Evaluation of safflower (Carthamus spp.) genotypes in multi-environment trials by nonparametric methods.

摘要

The objectives of this study were to identify of the 16 safflower (Carthamus spp.) genotypes that have both high and stable yield performance across different environments through apply nonparametric measures and study on the relationship among nonparametric stability statistics. Yield data of the 16 safflower genotypes selected from Iran/ICARDA joint project grown in 18 rain fed environments during 2003-05 in Iran was collected. Results of nonparametric tests of G x E and a combined ANOVA across environments indicated the presence of both crossover and usual crossover interactions and genotypes varied significantly for the grain yield. In this study, low values of sum of yield ranks and Shukla's stability variance, Rank Sum (RS), were associated with high yield, but the other nonparametric stability methods were not significantly correlated with mean yield. According to RS, three genotypes viz, G2, G14 and G16 were the best. Measure for general adaptability (TOP) high value indicates widely adapted genotype, according to TOP measure the genotypes G7 followed by G4 and G16 were relatively adapted. Regarding to RS and TOP, G16 (PI-537598) was the best genotype, which has high TOP value and low RS value also has the highest yield. So, could be selected as an adapted and stable genotype among all genotypes, although according to other nonparametric measures G16 was not selected as stable genotype.