Genetic Variability, Correlation and Path Coefficient Analysis in Advanced Generation of Brassica napus L.

The present study was conducted involving 62 F3 genotypes of Brassica napus L. at the experimental farm of Sher-e-Bangla Agricultural University, Dhaka, Bangladesh to ponder the genetic variability, phenotypic, genotypic and environmental coefficient of variation, heritability and genetic advance, correlation, path coefficient and genetic diversity analysis in a randomized complete block design (RCBD) with sixty-two genotypes (treatments) with three replications during November 2014 to February 2015. The investigations aimed to select the best segregating genotypes for the yield improvement of Brussica napus (rapeseed). Analysis of variance indicated that the genotypes were found significantly different for all the characters considered. The relative phenotypic coefficient of variation (PCV) was higher than the genotypic coefficient of variation (GCV) for all the traits investigated. The high GCV value was observed for the number of siliqua per plant (NSP), plant height (PH), silique length (SL), number of seed per silique (NSS) and seed yield per plant (SYP) indicated high broad sense heritability. The significant positive correlation with seed yield per plant (SYP) was found in plant height (PH) (0.368**), the number of primary branches per plant (NPB) (0.332**), number of secondary branches per plant (NSB) (0.382**), number of silique per plant (NSP) (0.549**), and siliqua length (SL) (0.037**). The results of path coefficient analysis uncovered that plant height (PH) (0.582), days to 50% flowering (50F) (0.390), days to maturity (DM) (0.575), number of primary branches per plant (NPB) (0.678), number of secondary branches per plant (NSB) (0.182),and thousand seed weight (TSW) (0.289) had a positive direct impact on seed yield per plant (SYP) and thus it was concluded that these traits could be exploited for the enhancement of yield potential of rapeseed. This study showed that based on the agronomic performance execution, genotypes G8, G14, G19, G21, G47, and G55 might be proposed for future hybridization program in Bangladesh and this could help rapeseed breeders to upgrade their breeding activities.