Diallel analysis for estimation of genetic parameters in oriental tobacco genotypes

Abstract

Oriental tobacco is one of the main types of tobacco (Nicotiana tabacum L.), which consists eight percent of the total world production in the world. The objective of this research was to estimate genetic parameters using diallel cross analysis to identify suitable parents used in Oriental tobacco breeding programs. Fifteen F1 progenies along with their six parents were planted in randomized complete block design with three replications in two separate experiments at Urmia Tobacco Research Centre, Iran in 2012. Combined analysis of variance for seven investigated traits consisting of fresh weight of leaf (FWL), dry weight of leaf (DWL), number of leaves (NL), length of leaf (LL), width of leaf (WL), length of stem (LS), and diameter of stem (DS), using Griffing's method 2, Model 1 showed significant mean squares of GCA and SCA for all traits except length of leaf indicating the importance of both additive and non-additive genetic effects for these traits. Baker ratios indicated that additive genetic effect were more important for investigated traits except number of leaves in which equal importance of both components was indicated. Good and poor general combiners were determined among parents for each investigated traits and finally a set of hybrids appeared to be significant SCA which could be used in Oriental tobacco improvement.