MORPHOLOGICAL DIVERSITY IN BURLEY TOBACCO GERMPLASM

Abstract

ICAR-CTRI, Rajahmundry, as a National Active Germplasm Site (NAGS) for tobacco germplasm, maintaining 138 burley tobacco germplasm. The morphological diversity present in this germplasm was investigated for estimating the existing variability for its further utilization. Out of 29 characters studied, the genotypes were found to be diverse for 26 traits and no variation observed for three traits viz., leaf type, inflorescence position and seed testa colour. Principal component analysis (PCA) with 26 diverse characters indicated that majority of the observed variation (91%) in the agromorphological traits found to be explained by eighteen PCA components. PCA1 alone explained 16% of the variation and was loaded mainly on eight traits viz., colour of leaf blade, leaf angle of insertion, inflorescence shape, leaf colour of midrib, width of leaf blade, plant shape, flower development of stamens and leaf length. The biplot of principal coordinates shows that the genotypes are scattered throughout the plot indicating the presence of morphological diversity among the entries. Clustering through unweighted pair groups produced grouping that defined four distinct clusters in 0 to 8 distance. The dissimilarity matrix worked out between 138 burley genotypes ranged from maximum value of 0.99 between YB-24 and Ky-171 to minimum value of 0.065 between Ky160 and Ky-171. The morphological diversity observed in the study indicates that the burley germplasm maintained at ICAR-CTRI is having sufficient diversity and can serve as a valuable source for burley genotype improvement.