Study of genetic divergence among Eucalyptus tereticornis clones through principal component analysis (PCA)

Eucalyptus tereticornis is one of the fastest growing multipurpose tree species. It is planted extensively under agroforestry and farm forestry. It was needed to estimate the genetic variability and contribution of yield contributing traits towards the total divergence. The PCA summarizes variability present in studied traits into utilizable form and to practical importance. Therefore, in the present study, eight clones of E. tereticornis were studied under field trial for their growth performance and contribution of individual traits towards total divergence were estimated. The eigene value of all three vectors (PCs) were found greater than one, which revealed that all the principal components explained a significant amount of variability present in traits. The proportion of variability explained by PC1 was 48.15 percent, by PC2 was 38.09 percent and by PC3 was 5.75 percent, all together these three vectors explained 92 percent of total variability. In PC1 and PC2, Plant height, biomass, leaf area, number of leaves, number of branches, leaf width and collar diameter were contributed positively towards the divergence hence the selection based on these traits will be rewarding. The times ranked contribution study also confirmed the contribution of L/W ratio (35.71%) and biomass (14.29%) towards the divergence. These traits are very important for the selection of parents in hybridization programs and effective selection of productive clones.