Impacts of erucic acid and glucosinolate content on genetic relationships between protein content and fatty acids of rape seed across environments

Abstract

Impacts of erucic acid content (EAC) and glucosinolate content (GSLC) on the genetic correlations between protein content (PC) and oil content (OC) or PC and fatty acid contents (FAC) in rape seed (Brassica napus L.) was analyzed by using unconditional and conditional methods related to genetic effects from the diploid embryo nuclear genes, cytoplasm genes and diploid maternal plant nuclear genes. A diallel mating design in two environments was conducted by using eight varieties along with their F1 and F2. It was found that there were significant relationships between PC and EAC or PC and GSLC of rape seed, and the conditional analysis method could be used to exclude the influences of EAC or GSLC for further revealing the actual genetic relationships between PC and OC or PC and FAC. The results from conditional analysis showed that when PC was conditioned on EAC or GSLC the conditional phenotypic and genotypic relationships between PC|EAC and oleic acid content or PC|GSLC and OC were changed to significantly positive, while those between PC|EAC and eicosenoic acid content or PC|GSLC and linolenic acid content became significantly negative. Thus, the levels of EAC and GSLC of rape seed could affect the correlations between PC and OC or PC and FAC. For the conditional genetic relationship analysis of different genetic systems, visible changes were found for many genetic correlation components from the embryo, cytoplasm and maternal plant between PC and OC or PC and FAC after eliminating the influences of EAC or GSLC, especially for conditional embryo dominance, cytoplasmic, maternal additive main covariances and conditional embryo dominance interaction covariance.