Relationship of yielding ability and heterosis effect of winter rapeseed F1 hybrids with genetic distance of parental lines

摘要

Breeding of oilseed rape hybrid varieties in Poland is based on CMS ogura hybridization system. The factor that has a decisive role in the advancement of this type of breeding is effective selection of parental forms of hybrids. Theoretically, greater heterosis effect is obtained in case of the crossing of lines with substantial genetic distance. Taking this into account, investigations of the relation between genetic distance of parental lines of hybrids, heterosis effect and seed yield of F1 hybrids were initiated. The plants material were 14 F1 hybrids of oilseed rape and their parental lines. These hybrids and their parental forms were evaluated for seed yield, agronomically important traits and their mid-parent heterosis (MPH) in field trials conducted in two localities for 2 years. Genetic distance between CMS ogura and restorer lines was evaluated on the basis of DNA polymorphism delineated with RAPD and AFLP markers and on the basis of enzymatic protein polymorphism. Phenotype similarity of parental forms was estimated on the basis of 9 phenotypic traits by Mahalanobis distance. The obtained results revealed statistically significant relationship between the genetic distance of the parental lines estimated by: AFLP markers; AFLP, RAPD markers and AFLP,RAPD, isozymes markers and seed yield of hybrids created with these lines. There was no association between genetic distance and mid-parent heterosis for seed yield. However, the information in this study points out to the possibility of selection of F1 hybrid combination, which assures high yield on the basis of genetic distance. The correlation between Mahalanobis distance and genetic distance has been recorded.