不同遗传背景籼稻白叶枯病抗性基因Xa21、Xa23品系的抗性评价

以含有水稻白叶枯病抗性基因Xa21和Xa23的材料为供体,以课题组选育不含Xa21或Xa23基因的材料为受体,通过杂交、复交等方法,并采用分子标记辅助选择（molecular marker-assisted selection,MAS）世代选择,将含有Xa21和Xa23基因的材料、含与不含Xa21或Xa23基因的姊妹系接种7种广泛使用的白叶枯病菌种生理小种,分析了这些材料白叶枯病的抗性。研究表明含有抗性基因Xa21的水稻材料抗性累计（HR、R、MR）所占比例依次为菌株HNA1-4、PXO86（84.62%）>YN24（82.14%）>GD1358（73.08）>PXO99（67.86%）>GDA2（63.33%）>FuJ（6.67%）,表明含Xa21基因材料对菌株FuJ所诱发的白叶枯病基本无抗病能力,但对于其他菌株,仍有36.67%~15.38%的材料易感病;含Xa23基因的材料在所有诱发菌株中抗性累计（HR、R、MR）均在76%以上,仍有23.02%~15.52%的材料对7种诱发菌株没有抗性。通过对菌斑长度变异系数大小的分析,表明含有Xa21或Xa23基因的材料对不同菌株抗病能力或对同一菌株的抗病能力不同材料有较大的变化。通过对诱发白叶枯病菌株间菌斑长度的相关性分析,表明含有Xa21的材料菌株GDA2或HNA1-4与对应的其他6菌株之间达到了显著或极显著正相关,含有Xa23基因的材料菌株YN24、GD1358、PXO86与对应的其他6种菌株间呈极显著正相关,含此2类基因材料抗性鉴定选取对应菌系可以提高选育效率。通过对姊妹系的分析表明,Xa21或Xa23基因的白叶枯病抗性与选育材料的背景有关。相关性分析表明,Xa21基因的材料抗性与亲本材料呈极显著正相关（R=0.5725^**）,Xa23基因材料抗性与亲本材料呈显著正相关（R=0.2212^*）。

Analysis of Xa21 and Xa23 of indica Rice Varieties in Different Genetic Background to Broad Spectrum Bacterial Blight Pathogens

The rice varieties of bacterial leaf blight resistance genes Xa21 or Xa23 were used as the donors, and the varieties without the genes as the receptor. By back crossing, composite crossing and other methods, combined with molecular marker-assisted selection (MAS), the varieties of Xa21 or Xa23, sister lines with or without Xa21 or Xa23 gene were inoculated with 7 widely used bacterial leaf blight pathogens, and the resistance of the varieties to the bacterial leaf blight was analyzed. The cumulative proportion of resistance (HR, R, MR) of the Xa21varieties was HNA1-4/PXO86 (84.62%)>YN24 (82.14%)>GD1358 (73.08)>PXO99 (67.86%)>GDA2 (63.33%)>FuJ (6.67%), and the varieties of Xa21 gene had no resistance to the bacterial leaf blight induced by FuJ, but for other pathogens, there were still 36.67%~15.38% of the varieties susceptible to diseases. The cumulative resistance (HR, R, MR) of the varieties of the Xa23 was over 76%, but there were still 23.02%~15.52% of the varieties that had no resistance to the 7 pathogens. Lesion length analysis, showed that the varieties of the Xa21 or Xa23 were resistant to different pathogen or the same pathogen. Different varieties had much variance. Lesion length analysis of of the7 bacterial leaf blight pathogens among the varieties of Xa21and Xa23 showed significant or extremely significant difference to GDA2 or HNA1-4 and other pathogens, and there was a extremely significant difference of YN24, GD1358 or PXO86 and other pathogens. The sister lines showed that bacterial leaf blight resistance of Xa21 or Xa23 was related to the donor of the varieties. Correlation of the varieties of Xa21 and parents showed extremely significant difference (R=0.5725 ^**), and there was a significant difference correlations of the varieties of Xa23 and parents (R=0.2212 ^*).