Genetic analysis of biochemical traits in F3 populations of rapeseed (Brassica napus L.)

The appropriate information on the biochemical characteristics of the plant is important for its usefulness in human health. The genetic basis for different brassica genotypes in terms of biochemical characteristics is important for the planning of effective breeding strategies. The present research was conducted to determine heritability, genetic advance and coefficient of correlation for biochemical traits in rapeseed. Breeding material comprising 10 parental lines and their 21 F3 populations was evaluated in the 2013-2014 at The University of Agriculture of Peshawar-Pakistan in a randomized complete block design with three replicates. For all studied traits, substantial differences were found among genotypes, parents, and F3 populations. Similarly, significant differences for all the studied traits with the exception of protein and glucosinolates have been recorded for parent vs. F3 populations. In most F3 populations, the heritability estimates associated with the maximum genetic advance for oil content, protein content, linolenic acid, erucic acid, and oleic acid were low or moderate. In comparison, moderate to high heritability coupled with maximum genetic advance, have been observed for glucosinolates for most F3 cross combinations. These findings show that selection in the early generation may be helpful in improving these characters. Oil content showed a negative and highly significant correlation with glucosinolate (rp=-0.50) and linolenic acid (rp=-0.57), so priority should be given to these traits to improve oil content. CA2 x DH5, DH7, and CA2 x DH7 performed better for oil content, protein content, and oleic acid, respectively, while DH2, DH5, and CA2 x DH8 showed better results for glucosinolates, linolenic acid, and erucic acid, respectively. These genotypes could be further utilized in rapeseed breeding programs.