江西稻瘟病菌稻巨座壳致病性分化年度动态变化

为明确江西水稻种植区稻巨座壳菌（稻瘟病病菌）的年际变化规律,本研究采用7个中国鉴别寄主与30个单基因鉴别品系两套鉴别寄主分别鉴定分析了2006-2018年间从江西37个水稻主要种植县市分离的1 161个稻瘟病单孢菌的生理小种、致病力、致病类型与无毒基因型等。研究结果表明,江西稻瘟病菌可以分成7群49个生理小种,其中ZA、ZB、ZC群为优势种群,ZB13为优势小种,出现频率为18.00%,以毒性较强的强致病力菌株为主;江西稻瘟病菌在生理小种构成、优势小种、致病力年际变化方面均具有3-5年的周期性;江西历年稻瘟病菌的致病类型较为丰富且存在年度差异,菌株致病类型占各年度总菌株数的82.79%-98.21%,优势致病型菌株占当年总菌株的3.57%-5.77%;历年稻瘟病菌的无毒基因个数为24-29个,其中Avr-Pizt、Avr-Piz5、Avr-Pik、Avr-Pik(C)在历年供试菌株中出现频率较高,说明与之相对应的抗瘟基因在江西抗病育种与抗性品种布局中具有较好的应用价值。

Dynamics of pathogenicity differentiation of Magnaporthe oryzae in different years in Jiangxi Province

Seven Chinese differential hosts and 30 single gene identification lines were used to identify and analyze the physiological races, pathogenicity, pathogenic type and avirulence genotype of 1 161 rice blast Magnaporthe oryzae strains isolated from 37 major rice-growing counties or cities in Jiangxi Province during 2006 and 2018. The results showed that all the Magnaporthe oryzae strains were divided into 49 physiology races belonging to 7 groups, of which ZA, ZB and ZC groups were dominant, and ZB13 was the dominant race with occurrence frequency of 18.00%. Magnaporthe oryzae strains of Jiangxi Province were mainly the strains of strong virulence, and they behaved a periodicity of 3 to 5 years in terms of dominance and virulence. The pathogenic types were relatively abundant and exhibited year’s difference. The annual percentage of pathogenic types was 82.79% to 98.21%, and the annual percentage of dominant pathogenic type was 3.57% to 5.77%. The number of avirulent genes of Magnaporthe oryzae in Jiangxi Province was found to be 24 to 29 in 2006-2018, and the avirulent genes of Avr-Pizt, Avr-Piz 5, Avr-Pik, and Avr-Pik(C) occurred more frequently, implying that the resistant genes corresponding to the avirulent genes have large application value in disease-resistant breeding in Jiangxi Province.