Analysis of genetic variation for morphological and agronomic traits in Iranian oriental tobacco (Nicotiana tabaccum L.) genotypes

To assess the genetic diversity for morphological and agronomic traits in Iranian oriental tobacco germplasm, 100 oriental and semi-oriental tobacco genotypes from the Urmieh Tobacco Research Center collection were evaluated in the field using a simple square lattice design with two replications. Some agronomic traits were measured on five randomly selected plants in each plot. Genotypes were clustered into similar groups using UPGMA based on squared Euclidean distance after data normalization. Four distinct groups were established. Discrimination function analysis performed to determine the accuracy of the grouping developed by cluster analysis showed that the total success rate of grouping was 97%. Among developed groups, groups 1 and 4 had the maximum Mahalanobis distance value of 67.4. Results revealed that the first three discriminant functions were significant, and their standardized discrimination function coefficients indicated that among the studied traits, days to 50% flowering, dry leaf yield and number of leaves per plant were the most important for discriminating among tobacco genotypes.