利用分子标记辅助选择改良水稻恢复系的稻瘿蚊抗性

以含有华南4种稻瘿蚊生物型显性抗性基因Gm6的籼稻材料KG18为供体,三系优质恢复系广恢998为受体,通过杂交、多次回交和自交结合分子标记辅助选择技术,将Gm6基因导入广恢998中。综合目标基因的分子检测、田间农艺性状表现以及遗传背景的回复率,筛选获得6个株系。采用稻瘿蚊生物型1和生物型4对这些改良株系进行人工接虫鉴定,6个改良株系的标葱率为0,表现免疫,而对照标葱率均在98%以上,表现高感;由改良株系组配的杂种F1标葱率在10%～20%,表现中抗。农艺性状分析表明,除1个株系在千粒重方面与对照广恢998有显著差异外,其余改良株系性状与对照无显著差异。

Improvement of Gall Midge Resistance for Restorer Line in Rice by Molecular Marker-Assisted Selection

Gm6, a dominant gene conferring resistance to the four biotypes of Asian rice gall midge (Orseolia oryzae Wood Mansion) occurred in South China from the donor KG18, was introduced into the restorer line Guanghui 998 with good grain quality and poor gall midge resistance, by using backcross breeding and molecular marker assisted selection. Six elite improved lines were developed based on the results of molecular marker assisted analysis, the recovery ratio of genetic background and the performance of agronomic traits. Evaluation of resistance to Chinese gall midge biotype 1 and biotype 4 was carried out. All the improved lines were immune to the pest with the ratio of silver shoots of 0 whereas the check Guanghui 998 were highly susceptible with the ratio of silver shoots of 98%. The hybrid F1, derived from the improved lines, showed moderate resistance against gall midge with the ratios of silver shoots ranging from 10% to 20%. The investigation on agronomic traits of the improved lines showed that there was no significant difference between the improved lines and the check except for 1000 grain weight between one line and the check Guanghui 998. The improved lines could be used for breeding hybrid rice with higher gall midge resistance.