نوع مقاله : مقالات پژوهشی
عنوان مقاله English
نویسندگان English
Introduction: In bean breeding programs, the ultimate goal of researchers is to produce varieties with high yield potential to increase production in different environments. Due to the differences in the adaptability of genotypes in different environments, the yield of genotypes fluctuates in different environments, which is known as the genotype × environment interaction (GEI) and is the result of the different phenotypic responses of genotypes to environmental changes. It is of particular importance to understand the type and nature of the interaction and to obtain the figures that show the least reaction to the interaction. To account for GEI, breeders evaluate genotypes in multiple environments to identify genotypes with high yield and stability and genotypes that have a non-significant GEI are considered stable genotypes. There are various methods, such as parametric and nonparametric methods, to evaluate interaction effects but the best result is achieved when a genotype shows similar results of stability with different evaluation methods. Therefore, identifying and introducing stable cultivars with high grain yield in different environmental conditions is one of the priorities of breeding programs for this crop. For this purpose, this study was conducted to investigate the stability of 13 chiti bean genotypes using multivariate methods.
Materials and methods:
In order to compare the yield and study the compatibility of bean genotypes, 12 bean genotypes along with the Kosha cultivar (check) were studied in a randomized complete block design with three replications in four regions: Khomein, Boroujerd, Shahrekord, and Zanjan for 2 years. The F-test of sources of variation was performed based on the arithmetic mean square expectation, assuming randomness of years and locations (environments) and fixed genotypes. To determine the stability and compatibility of genotypes, AMMI multivariate methods and BLUP-based linear mixed model were used, and WAASBi and WAASBYi stability quantities were calculated to quantify stability.
Results:
A combined analysis of variance was performed assuming randomness of years and locations (environments) and fixed genotypes and it showed that the interaction effects of genotype × location, year × location and genotype × year × location were significant. The main effect of genotype, the main effect of environment (sum of main effects and interaction effect), and the interaction effect of genotype × environment (sum of dual and triple effects) explained 15, 39, and 40 percent of the total sum of squares, respectively. AMMI analysis of variance showed that the first to seventh principal components were significant and together explained nearly 100% of the variation in the genotype × environment interaction. The first and second principal components explained nearly 76% of the sum of squares of the GEI. Genotypes G11, G9 and G6 had the lowest values of the IPCA1, and among them, only genotype G9 had a yield higher than the average total yield, which was introduced as a stable genotype with high general adaptability to all environments. Genotypes G8, G6, and G11 had the lowest values of the second principal component of IPCA2; therefore, considering the yield, genotype G6 can also be introduced as a stable genotype in all environments. AMMI2 biplot showed compatibility of genotype G12 with Shah1 and Zan2, genotypes G2, G3 and G4 with Boro1, genotypes G9 and G13 with Khom1 and Khom2 and genotypes G1 and G8 with Boro2 environments. Based on the simultaneous selection criterion based on average grain yield and WAASB stability index, genotypes G7, G9, G8, G6, G1 and G3 with the highest WAASBY value were stable genotypes with high grain yield. Based on the biplot of grain yield versus weighted average absolute scores (WAASB), genotypes G7, G8, and G9 located in the fourth quartile had higher yields than the average yield of genotypes and were more stable than other genotypes. Finally, based on equal importance for yield and stability, G11 and G4 are stable and low-yielding genotypes, G6, G7, G8 and G9 are stable and high-yielding genotypes, G1, G3 and G5 are unstable and high-yielding genotypes, and finally G10, G12, G13, G20 and G2 are unstable and high-yielding genotypes.
Conclusion: Due to the use of the mixed model and all components in calculating the WAASBY index, it seems that this index is better than other indices for calculating the stability and compatibility of genotypes. Therefore, using this index, genotypes G9, G7, G8, and G6 were ranked in the top ranks, respectively, and were selected as the best genotypes.
کلیدواژهها English
