Genetic analysis of common bean (Phaseolus vulgaris L.) genotypes for root traits, yield components and seed yield

Screening genotypes with robust root architecture is preeminent to increase considerably bean (Phaseolus vulgaris L.) seed yield. The survey consisted to evaluate the genetic variability, estimate  broad sense heritability, genetic advance, and determine  the correlations for root traits, seed yield, and its components for ten bean lines. The field trial was laid out in a randomized complete block design with three replications. Data were submitted to the analysis of variance (ANOVA) and multivariate analyses using STATGRAPHICS PLUS version 16.1 and R version 3.5.1 statistical package programmes, respectively. ANOVA showed that the results revealed significant differences among the bean lines denoting a wider genetic variability for root traits, seed yield and its components. Principal component analysis displayed the relationship between traits and genotypes, indicating a substantial level of variability among the genotypes for root traits, yield components and seed yield; hence, it could be exploited for more improvement bean yield. Cluster analysis confirmed a sufficient genetic variability; thereby, the distal clusters could be used for further improvement bean yield and root traits. All traits exhibited high values of broad sense heritability suggesting these characters could be improved by selection. High broad sense heritability associated to high genetic advance was observed for root growth angle and 100-seeds weight. This attests that additive gene effects were involved in the heredity of these traits, and they can be readily fixed in the genotypes by selection in the early generations. The number of basal roots exhibited significant and positive correlation with the number of adventitious roots; hence, these traits could be considered the main components and selection may be effective in improving the bean root system. The bean lines Bigarré, FEB192, GLP190 S, ECA-PAN021, Gros Rouge and Petit Rouge could be used as elite material in breeding programmes for seed yield and root traits.