MORPHOLOGICAL DIVERSITY AND RELATIONSHIPS PATTERNS AMONG A SET OF AIRCURED EXOTIC GERMPLASM ACCESSIONS OF NICOTIANA TABACUM

Abstract

The genetic variability in the germplasm is always essential in breeding programme to improve the yield and adaptability, impart resistance to biotic and abiotic factors etc. Low degrees of variability captured in the cultivated genotypes leads to genetic vulnerability and lower marginal yield gains. At ICAR-CTRI a study was conducted to investigate the genetic diversity of 53 exotic aircured lines collected from Japan using morphological traits. Thirty morphological observations were recorded and among them 26 characters with diversity were subjected to principal component analysis (PCA). Ten PCA components were formed based on the eigen values. Further, the dissimilarity index and relationship between the genotypes were analysed. Clustering through unweighted pair groups defined four distinct clusters in 0 to 0.5 distance. The dissimilarity matrix was worked out between 53 genotypes and the maximum dissimilarity value was found between genotypes Aizu Katai Kari and Connecticut-7-D (0.894) and the minimum dissimilarity value was between Rengeha and Tennessee Red (0.143). The morphological diversity studied indicates that the exotic germplasm collected and maintained at ICAR-CTRI, serves as a variability hub for tobacco improvement.