Multivariate Analysis as a Tool for Indirect Selection of Common Bean Genotypes (Phaseolus ( vulgaris L) for Soil Acidity Tolerance under Field Conditions

Abstract

A field experiment was conducted to evaluate soil acidity tolerance of 25 common bean (Phaseolus vulgaris L.) genotypes on lime-treated and lime-untreated acid soils. The twenty- five common bean genotypes were tested in a randomized complete block design with two replications per treatment in 2009 in western Ethiopia. Morpho-agronomic parameters were recorded to evaluate the genotypes. Multivariate methods, including principal component and cluster analysis were used to assess the patterns of morpho-agronomic variation to group the genotypes into distinct categories. The genotype bi trait (GT) bi-plot was used to identify the best traits that are important to identify tolerant genotype and to know the relationships between traits and genotypes. The principal component analysis indicated that the first three principal components contributed 64.6 and 66.1% of the total variability among the 25 common bean genotypes grown on the lime-untreated and lime-treated soils, respectively. Among the measured traits, plant height, number of pods per plant, days to pod setting, grain yield, days to flowering and maturity, biomass yield, and 100 seed weight were the parameters that most significantly caused the variations among the genotypes. Genotype by trait (GT) bi-plot led to grouping of the tested genotypes into four categories based on PC1 and PC2 values and also enabled to identify traits such as number of pods per plant, plant height, pod length, 100 seed weight, and grain yield, which were found to be the most responsive characters in evaluating the genotypes for tolerance to soil acidity. The cluster analysis led to classification of the 25 common bean genotypes in to four groups, the first group (cluster) of which contained four genotypes of BILFA material (new BILFA 38, new BILFA 58, New BILFA 61, and new BILFA 60) that outperformed genotypes in the other group (clusters) when grown on lime-untreated acid soil. In conclusion, the results of this study have revealed that multivariate analysis can be used as an indirect method of selecting high-yielding common bean genotypes having the most important desirable traits that contribute to soil acidity tolerance.