Genetic variability, correlation and path analysis in advanced lines of rapeseed (Brassica napus L.) for yield components

Abstract

The present research was carried out to determine the best selection criteria for yield improvement in rapeseed (Brassica napus L.). Nine genotypes of Brassica napus were sown at Oilseeds Research Institute, Faisalabad, during the years 2011- 2012, to evaluate the means and components of variability (genotypic and phenotypic), heritability (h2 B.S), correlation (genotypic and phenotypic) and path analysis for yield and various yield components. At phenotypic and genotypic level, seed yield/plant had significant positive correlation with plant height, seeds/plant and siliqua/plant. A positive and highly significant genetic relationship was found between plant height and seeds/plant, siliqua length and seeds/siliqua, days to maturity and 1000 seed weight, days to flowering and seeds/plant, days to maturity and seeds/plant. Path coefficient revealed that the seeds/siliqua, 1000 seed weight, days to flowering, days to maturity and seeds/plant had direct positive contribution towards seed yield per plant. For rapeseed breeding seed per plant was the variable with maximum potential of selection for seed yield improvement because this trait possessed high h2 B.S, highly significant positive correlation and maximum positive direct effects with yield.