摘要
通过多菌系接种鉴定及抗谱分析,并与目前国际上已知抗白叶枯病基因比较,证明在水稻抗源C4064中含有一个新的抗白叶枯病基因,暂命名为Xa32(t)。应用分离集团分析法(BSA),借助SSR和EST等分子标记,对该基因进行了分子标记定位。通过对F2分离群体及F3家系单株进行遗传连锁性检测,发现6个位于水稻第11染色体长臂末端的分子标记RM27256、RM27274、RM2064、ZCK24、RM6293和RM5926与Xa32(t)基因连锁。它们与Xa32(t)基因间的遗传距离分别为2.1、1.0、1.0、0.5、1.5和2.6cM。其中标记RM6293和RM5926位于染色体近端粒一侧,其他4个标记RM27256、RM27274、RM2064和ZCK24位于基因的另一侧。将Xa32(t)定位在水稻第11染色体长臂末端2.0cM范围内。
The rice bacterial blight （BB）, caused by Xanthmonas oryzae pv. oryzae （Xoo）, is the most devastating bacterial disease of rice worldwide. Use of resistant varieties has been thought the most economical and environment-friendly approach to control BB of rice. Since the rapid changes of the pathogenicity of the pathogen （Xoo）, new BB resistance genes are always needed for rice breeding. Here, we report the identification and molecular mapping of a new BB resistance gene from Oryzae ustraliensis. Based on the resistance spectrum analysis, we identified a new rice germplasm, C4064, for bacterial blight （BB） resistance. Leaf-cutting innoculation assays showed that C4064 was resistant to Xoo strains P1 （PXO61）, P4 （PXO71）, P5 （PXO112）, P6 （PXO99）, P7 （PXO145）, P8 （PXO280）, P9 （PXO339）, and KX085, but susceptible to P2 （PXO86） and P3 （PXO79）. Comparison of resistance spectrum with that of all the known BB resistance genes and genetic analysis revealed that the rice germplasm C4064 harbored a new BB-resistance gene, designated as Xa32（t）. To molecularly map Xa32（t） gene, Bulked Segregant Analysis （BSA） was adopted to survey SSR and EST molecular markers. Out of 299 markers tested, six markers RM27256, RM27274, RM2064, ZCK24, RM6293, and RM5926 on rice chromosome 11 displayed polymorphism between the S-pool and R-pool. By analyzing the F2 and F3 populations, the gene Xa32（t） was mapped on the long arm of rice chromosome 11. Linkage analysis revealed that molecular markers RM27256, RM27274, RM2064, and ZCK24 were located between Xa32（t） and the centromere of the chromosome, with genetic distances of 2.1, 1.0, 1.0, and 0.5 cM to Xa32 （t）, respectively; while RM6293 and RM5926 were located on the other side of Xa32（t）, with genetic distances of 1.5 and 2.6 cM to Xa32（t）, respectively. Thus, the new BB-resistance gene Xa32（t） was mapped within a length of 2.0 cM on the long arm of rice chromosome 11. The results of this study will be usef
出处
《作物学报》
CAS
CSCD
北大核心
2009年第7期1173-1180,共8页
Acta Agronomica Sinica
基金
国家高技术研究发展计划(863计划)项目(2006AA10Z106)
中央级公益性科研院所基金项目(2060302-2-08)资助
