水稻抗白叶枯病新基因Xa39分子标记有效性的评价

Xa39是一个对水稻白叶枯病具有广谱抗性的显性新基因,在水稻抗白叶枯病育种中具有良好的应用价值和前景。在前期研究中,我们将该基因定位在水稻第11染色体上。本研究利用携带Xa39基因的供体亲本FF329与受体亲本BT4、BT6、BT12、BT18杂交培育出4FL10、4FL14、4FL17、4FL21四个育种F2分离群体,结合人工接种抗病性鉴定,对3个与Xa39紧密连锁的分子标记进行分子标记辅助选择(MAS)有效性比较,筛选高效的PCR分子标记。结果表明,标记RM26985和RM206在上述4个群体中的MAS准确率分别达到95.81%和93.61%,同时使用两者其准确率达到95.59%,上述2个标记在水稻白叶枯病抗性改良育种中可以提高Xa39的选择效率。

Evaluation of Selective Efficiency of Molecular Markers Linked with a Novel Gene Xa39 Resistant to Bacterial Blight in Rice

Xa39 is a novel and dominant resistance gene with broad spectrum for bacterial leaf blight in rice. In previous study, this gene was mapped on chromosome 11. In present study, FF329 carrying Xa39 gene as donor parent and BT4, BT6, BT12, BT18 as recipients were used to develop four F₂ segregation populations (4FL10, 4FL14, 4FL17, 4FL21). Combining artificial inoculation with phenotype identification of bacterial leaf blight, the validity of three molecular markers tightly linked with Xa39, and two co-dominant molecular markers was investigated for marker-assisted selection (MAS). The results showed that the accuracy of marker RM26985 for MAS was 95.81% and that of marker RM206 was 93.61% in the four populations. The accuracy of two markers RM26985 and RM206 used simultaneously for MAS was up to 95.35%. Therefore, RM26985 and RM206 can be used as effective markers in MAS for Xa39 in rice breeding program.