Comparision of cluster formation by mahalanobis’ D2 and metroglyph analyses in groundnut (Arachis Hypogaea L.).

Fifty genotypes of groundnut were classified into five and seven clusters in D2 and Metroglyph methods of analyses respectively. Harvest Index and 100-seed weight were the main contributors to total divergence as per metroglyph analysis. The characters on X and Y axes in scattered metroglyph diagram determine the grouping of genotypes, hence it poses a problem for judicious selection of these characters. The comparative study of these methods indicated that metroglyph analysis would be suitable for preliminary grouping when large number of genotypes are considered at a time. The differences between the two methods, the number of clusters formed, inter cluster distance, characters considered for grouping and superimposition of genotypes within the cluster indicated that D2 analysis was more effective compared to metroglyph analysis.

Character association and path analysis in groundnut (arachis hypogaea l.).

Correlation and path co-efficient analysis were carried out for pod yield and its component characters in 50 genotypes of groundnut. The genotypic correlation co-efficients were found to be of relatively higher magnitude than the corresponding phenotypic correlation co-efficients, indicating strong inherent association between the characters. Pod yield displayed significant positive association with kernel yield per plant, mature pods per plant, total pods per plant, harvest index, 100-seed weight, root weight, plant height and shoot weight. Path co-efficient analysis revealed high direct effects of kernel yield per plant and harvest index on pod yield. Hence, it would be rewarding to give due importance on the selection of these characters for rapid improvement in pod yield of groundnut.