Relationships and variability of agronomic and physiological characters in mungbean
This study was conducted to determine the variability, heritability and correlations among agronomic and physiological characters of mungbean (Vigna radiata (L.) Wilczek) and to identify their direct and indirect effects on seed yield. Fifty six mungbean accessions were evaluated at Suranaree University of Technology Farm, Nakhon Ratchasima, Thailand using a randomized complete block design with 4 replications. Fourteen characters were collected and analyzed for genotypic coefficient of variation, phenotypic coefficient of variation, environmental coefficient of variation, heritability estimates in broad sense, phenotypic and genotypic correlation coefficients and path coefficients. It was found that genotypes differed significantly for all characters studied. The highest heritability values were recorded on days to flowering and pod length. Seed yield was significantly and positively correlated with pods per plant, clusters per plant, total dry matter (TDM), seeds per pod, seeds per plant, biomass, leaf area index and branches per plant, and negatively correlated with days to maturity. Clusters per plant showed the highest positive direct effect on seed yield followed by 100 seed weight, seeds per pod, TDM and pods per plant. However, the effect of 100 seed weight was substantially minimized by the negative indirect effects of clusters per plant, pods per plant and seeds per pod. These results demonstrate that clusters per plant, seeds per pod, TDM and pods per plant should be used as selection criteria for yield improvement in mungbean.
Key words: Agronomic characters, correlation analysis, mungbean, path coefficient analysis, physiological characters, variability, Vigna radiata, yield components.