GENETIC DIVERSITY AMONG MUTANT GERMPLASM ACCESSIONS OF NICOTIANA TABACUM AS DETERMINED BY MORPHOLOGICAL PARAMETERS

Abstract

Low levels of variability prevailing in the cultivated genotypes of crops leads to genetic vulnerability and lower/marginal yield gains. Creating variation using mutation breeding is one of the options to overcome this problem. ICAR-CTRI is maintaining 35 mutant lines (including natural mutants) which is harboring a vast genetic variability. The diversity of 29 agro-morphologcal characters was studied in these lines for assessing the suitability of these lines for tobacco breeding programme. Principal component analysis (PCA) of the recorded characters indicated that, out of seven components obtained, PCA1 PCA2 are contributing major variability (about 41%). Grouping of the genotypes based on UPGMA produced four distinct clusters with 6.5 distance. The dissimilarity index (DI) showed that the mutants RT 63-2 and CM 3-1 were distantly related with the maximum value of 0,867 and similarly the mutants R90-1 and R91 1 were closely related with low DI value of 0.125 The genotypes were varying twenty six characters and such genotypes with diverse morphological traits can be utilized in tobacco breeding for yield and quality improvement.