多亲本复合杂交提高油菜杂交种的产量

Yield improvement of hybrid variety through multiple crosses in Brassica napus

提高油菜品种的产量水平依靠优良亲本系的选育和杂种优势的充分发挥。利用复合杂交技术,选用具有优良性状互补和不同遗传背景的材料为亲本,分别培育陕2A细胞质不育系统的保持系和恢复系,然后通过分子标记估算遗传距离预测杂种优势,成功选配出高产优质杂交油菜品种中油杂12。与湖北省大面积推广的常规双低品种中双9号相比,中油杂12在两年多点的品种区域试验中平均增产15.03%,比目前长江流域种植的当家品种中油杂2号增产5.62%,成为湖北省有史以来第一个在区试中产量超过3000 kg.hm-2的油菜品种,也是在国家油菜品种区试中第一个比中油杂2号增产5%以上的品种。由于具有稳定的高产及高含油量性状,中油杂12的产油量在国家区试中均稳定在1100 kg.hm-2以上,平均比对照中油杂2号增加了9.06%。讨论了复合杂交的育种技术对提升细胞质雄性不育系统的保持性能及杂交种产量水平的作用,对油菜杂种优势利用技术改进和高产育种具有重要的指导意义。

The yield and quality of rapeseed varieties have been improved significantly after breeding practice over more than twenty years in China. Compared to those varieties developed in industrialized countries,however, the yield of Chinese rapeseed varieties is still low. Further improvement of rapeseed yield relies on the development of elite parental lines and the full exploitation of heterosis for hybrid production. This study made use of germplasm with traits complementary to each other with different genetic background,to breed the maintainers and restorers of Shaan 2A cytoplasmic male sterility first, then to predict the heterosis by the evaluation of genetic distance between parental lines. Based on the heterosis predietion,a hybrid variety Zhongyouza 12 with high yield and good quality was successfully developed. The yield of Zhongyouza 12 not only surpassed Zhongshuang 9,which is a largely extended open pollinated variety in Hubei province,by 15.03%,but also over yielded Zhongyouza 2,which has been the highest yielding hybrid along Yangtze river basin, by 5.62%, becoming the first rapeseed variety which over yielded Zhongyouza 2 in national trials and with yield over 3 000 kg · hm^-2 in Hubei provincial trials. Due to the stable yield and high oil content, the oil yield of Zhongyouza 12 was stabilized above 1 100 kg · hm^-2 in national trials,increase by 9.06% compared to Zhongyouza 2. The effects of multiple crosses on the elevation of maintaining ability of cytoplasmic male sterility and the realization of yield potential are also discussed.