水稻抗性基因Pi对福建省稻瘟病菌优势菌群的抗性分析

【目的】抗病品种的合理利用和布局是实现水稻抗瘟持久化的关键因子之一。为明确水稻24个抗性基因在福建省的抗病性及其应用前景,【方法】首先分别采用全国稻瘟病菌生理小种鉴别品种和CO39近等基因系来鉴定2012-2015年间从福建省各稻区种植的普感品种丽江新团黑谷上采集的347株稻瘟病菌单孢菌株的生理小种类型和致病型,再测定24个抗性基因对福建省稻瘟病菌的抗性。【结果】根据全国稻瘟病菌生理小种鉴别品种对菌株的抗感反应,可将供试稻瘟病菌的生理小种划分为6个群36个生理小种,其中ZA、ZB和ZC为主要种群,ZC15、ZD7和ZB15为优势生理小种。根据CO39近等基因系的接种结果,将供试稻瘟病菌划分为17个致病类型,其中I34.1为优势致病型。供试的24个抗性基因对347株福建省稻瘟病菌菌株的抗性频率不同,抗谱为9.80%~89.91%。其中,Pi-k~m、Pi-7(t)、Pi-9(t)、Pi-k~p、Pi-k、Pi-k~h、Pi-z~5和Pi-ta(1)等8个抗性基因的抗病性较强,抗谱均高于70.00%。【结论】说明这8个抗性基因在福建省具有较好的应用前景,育种时可以考虑联合利用这些抗性基因。同时,实验结果表明,这8个抗性基因对主要生理小种的抗谱和主要致病型的抗谱均值高于69.00%,与其对所有测试菌株的抗谱吻合。说明利用稻瘟病菌的优势种群或优势致病型来鉴定水稻品种的抗病性是可靠的。

Analysis on Resistance of Pi Genes to Predominant Races of Mangnaporthe oryzae in Fujian Province,China

【Obiective】 The rational utilization and deployment of the blast resistance in rice varieties are key factors that ensures the durability and effectiveness of resistance genes. To determine the resistance and utilization potential of 24 single major resistance genes in Fujian Province, 【Method】 we tested the physiological races and pathotypes of 347 single spore isolates of Magnaporthe oryzae which were isolated from susceptible rice cultivar “Lijiangxintuanheigu” from different rice growing areas within Fujian Province between 2012-2015 by using seven Chinese host differentials and six CO39 near isogenic lines (CO39 NILs) respectively. We further performed an assay to monitor the resistance frequencies of 24 single resistance genes with these isolates. 【Result】 Subsequently, we observed that the seven Chinese host differentials clearly differentiated the 347 isolates into six distinct groups with 36 physiological races. The dominant groups were ZA, ZB and ZC, and the dominant physiological races were ZC15, ZD7 and ZB15. In addition, we noticed that the six CO39 NILs differentiated the 347 isolates into 17 pathotypes with I34.1 as the dominating pathotypes. Particularly, the resistance spectrums associated with the 24 resistance gene were larger and ranged from 9.80 to 8991% when inoculated with the 347 isolates. For the eight resistance genes Pi km, Pi 7(t), Pi 9(t), Pi kp, Pi k, Pi kh, Pi z5 and Pi ta(1), their resistance spectrums were above 70.00%. 【Conclusion】 These results indicated that the eight resistance genes could be successfully deployed in Fujian Province, and further demonstrated that rice breeding approaches could be combined with multiple resistance genes in widely grown hybrids or cultivars. Furthermore, the recorded resistance spectrums of eight genes for dominant physiological races and pathotypes were above 69.00% and adequately proved that the use of dominant physiological races or pathotypes as a method for identifying resistance or resistance spectrums in rice cultivars was reliable.