Correlation, path coefficient and principal component analysis of yield components in mung bean [Vigna radiata (L.) Wilcezk] accessions

Adequate knowledge on the identification of the most important yield contributing traits would help in improving seed yield of mung bean by using appropriate selection indicators. Thus, this research work aimed at studying relationships among yield contributing traits and estimating the direct and indirect effects of these traits on seed yield of 20 mung bean accessions evaluated at three major agro-ecologies (forest, derived savanna and savanna) in southwest Nigeria. Results obtained from correlation analysis revealed that significant and positive relationship existed between pairs of seed yield/ ha with days to first flowering (r=0.27**), number of pods/plant (0.32**), number of seeds/pod (0.14*) and pod yield/plant (0.91***). Path analysis showed that pod yield/plant had the highest positive direct effect on seed yield/ha (0.91), followed by pod length (0.40), days to 70% maturity (0.12), days to 50% podding (0.10), days to first flowering (0.04) and number of pods/ plant (0.01). Similarly, pod yield/plant exhibited positive indirect effect through days to first flowering, days to 50% flowering, days to 50% podding, number of pods/plant, days to 70% maturity and pod length. Principal component analysis revealed five component axes that accounted for 89.45% of the total variation. The first three components had eigenvalues greater than 1.0 and accounted for 70.48% of the total variation. The first principal component was associated with days to first flowering, days to 50% flowering and days to 50% podding with negative loadings. The traits that contributed the most positive loadings to the second component were seed yield/ha and number of pods/plant. The third component was associated with pod length and number of seeds/pods with positive loadings. Identified relationships could assist plant breeders in genetic improvement of seed yields of mung bean.