Electronic Journal of Plant Breeding (Mar 2021)
Tailoring genetic diversity of greengram genotypes through principal component and cluster analysis
Abstract
One hundred genotypes of green gram were evaluated at the Pulse Research Station, AAU, Vadodara, Gujarat during summer 2019 for genetic diversity study based on six biometrical traits and to identify the best performing genotype suited to Gujarat. To determine the extent of variability existing among 100 green gram genotypes, Principal Component Analysis (PCA), cluster analysis and the inter-relationship existing between biometrical traits through Pearson’s correlation analysis were carried out. The highest correlation was observed among the seeds per pod and pod length, pods per plant and the number of branches per plant. 100 seed weight had a negative and significant correlation with plant height, the number of branches per plant and pods per plant. According to the principal component analysis, two principal components (PCs) had eigenvalues more than unity and accounted to explain 67.37 per cent of the total variance that exists among six traits. PC1 and PC2 accounted for 39.88 and 27.49 per cent proportion of total variance, respectively. All traits were highly loading on PC1 except pod length and 100 seed weight which were loading on PC2. Three different groups of biometrical traits were observed in the component pattern. A hundred genotypes were classified into eleven clusters through the hierarchical cluster analysis method. Cluster I comprised a maximum number of genotypes followed by cluster VI, cluster II and cluster VII. Based on the cluster analysis, it could be recommended that crosses could be made between the genotypes of Cluster VIII and IX, Cluster VIII and X and Cluster X and XI which are distantly related. Lower plant height was observed in the genotypes under Cluster VIII and clusters X consisted of tall genotypes with a higher number of branches per plant. The highest pod length, pods per plant and seeds per pod were recorded under cluster IX. Cluster IV had a significantly higher 100 seed weight. Intraclass correlation (R2) was the highest for pod length followed by plant height and seeds per pod indicating that these traits played an important role in divergence.
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