Study on Heterosis and Combining Ability in Oil Content in Brassica napus L.in Spring Rape Area

Thirty reciprocal crosses were made with six high-oil black seeded Brassica napus L.lines as parents with different oil content and genetic background,based on the Griffing ModelⅠdesign, and a total of 36accessions including 30reciprocal crosses and six parents were planted in a randomized complete block design in spring rape area in Zhangye of Gansu province.Heterosis and combining ability in oil content were analyzed.The results showed that 80.00%of the crosses exhibited positive mid-parent heterosis,and only 20.00% of the crosses exhibited positive over-parent heterosis.The broad sense heritability of oil content was 97.83%and the narrow sense heritability of oil content was 78.19%.The variances of both general combining ability(GCA)and specific combining ability(SCA) in oil content were significant at 0.05or 0.01level,and the reciprocal cross effect of oil content was highly significant(P0.01).The analysis showed that the inheritance of oil content in Brassica napus L.was mainly controlled by additive gene effect and affected by non-additive effect simultaneously.It was suggested that high-oil line with high GCA should be used as parents in hybrid rapeseed development for high oil content,moreover,the reciprocal effect should be considered in the determination of spring rapeseed hybrid crosses.