Genetic variability and heritability estimates of morphological traits in F2 populations of rapeseed (Brassica carinata L.)

Abstract

This study aimed to estimate genetic variability, heritability, and genetic advance for morphological characters in Brassica carinata L. A total of 22 genotypes comprised of six parental lines and their 16 bulk F₂ populations were evaluated in a randomized complete block design with three replications at The University of Agriculture Peshawar during 2013-14. Data were recorded on days to 50% flowering, primary branches plant^-1, main raceme length, pods on main raceme, pod length, number of seeds pod^-1, 100-seed weight, and seed yield plant^-1. Significant genetic differences were observed for all the traits studied. Among parental lines, C-93 performed better for primary branches plant^-1 (11 branches), main raceme length (59.57 cm), pods on main raceme^-1 (33 pods), and seeds pod^-1 (15 seeds), C-95 for pod length (4.04 cm) and seed yield plant^-1 (12.26 g). Among F₂ populations, C-97 x C-88 performed better for main raceme length (73.20 cm), pods on main raceme (41 pods), C-88 x C-93 for pod length (4.95 cm), seeds pod^-1 (18 seeds), and seed yield plant^-1 (14.71 g). Moderate (30 < h² ≤ 60) to high (h² > 60) broad-sense heritability was observed for all morphological traits with maximum genetic advance, hence indicated that selection could be effective in the early generation for the improvements of these studied traits. Generally, cross combinations C-88 x C-93, C-97 x C-95, C-90 x C-93, and C-97 x C-88 performed better than their parental lines for morphological (primary branches plant^-1, seeds pod^-1, and seed yield plant^-1) traits and could be exploited for varietal development in future brassica breeding programs.