侵染优质稻美香占2号的稻瘟病菌生理小种鉴定及无毒基因分析

为明确优质稻种美香占2号的抗瘟性,并为其合理布局以及与不同品种的轮换种植提供科学依据,利用7个中国鉴别品种和11个抗稻瘟病单基因系,对2013—2017年自广东省美香占2号品种上分离获得的50株稻瘟病菌Magnaporthe oryzae菌株进行生理小种鉴定和无毒基因型分析。结果显示,50株稻瘟病菌菌株被鉴定为11个生理小种,其中优势小种分别为C13、B13、B01、B05和C05;50株稻瘟病菌菌株对IRBLkh-K3(仅含Pik-h基因)、NIL-e1(仅含Pi50基因)、IRBL9-W(仅含Pi9基因)和IRBLzt-T(仅含Piz-t基因)4个抗稻瘟病单基因系表现出极低的毒性,频率分别为4%、6%、6%和8%;对IRBLz-Fu(仅含Piz基因)、IRBLkp-K60(仅含Pik-p基因)和IRBLi-F5(仅含Pii基因)3个抗稻瘟病单基因系表现出相对较高的毒性,频率分别为88%、86%和80%;自美香占2号以及其它4个主栽品种上获得的70株稻瘟病菌菌株被聚为不同类群;2003—2007年供试菌株中无毒基因AvrPi9、AvrPiz-t、AvrPi50和AvrPik-h的出现频率较高,无毒基因AvrPi1、AvrPita2、AvrPi2和AvrPish的出现频率中等,无毒基因AvrPii、AvrPik-p和AvrPiz的出现频率较低。

Identification of physiological race and analysis avirulent genes for isolates of rice blast infecting from rice variety of Meixiangzhan 2

In order to improve the blast resistance of Meixiangzhan 2, rational distribution and rota-tion planting of different varieties, 50 Magnaporthe oryzae isolates collected from the host of Meixiang-zhan 2 in Guangdong Province from 2013 to 2017, were tested for their pathogenicity and the corre-sponding avirulence genotypes against seven Chinese differential cultivars and 11 blast monogenic lines. The results showed that 11 physiological races were identified and the predominant races were C13, B13, B01, B05 and C05, respectively. 50 M. oryzae isolates showed extremely low virulent to IR-BLkh-K3 (only including Pik-h gene), NIL-e1 (only including Pi50 gene), IRBL9-W (only including Pi9 gene), and IRBLzt-T (only including Piz-t gene) four blast monogenic lines with frequency of 4%, 6%, 6% and 8%, respectively, and showed relatively high virulent to IRBLz-Fu (only including Piz gene), IRBLkp-K60 (only including Pik-p gene) and IRBLi-F5 (only including Pii gene) three blast monogenic lines with frequency of 88%, 86% and 80%, respectively. 70 M. oryzae isolates isolated from Meixiangzhan 2 and the other four main varieties were clustered into different groups. From 2013 to 2017, the occurrence frequency of avirulent genes AvrPi9, AvrPiz-t, AvrPi50, and AvrPik-h in all strains was higher, the occurrence frequency of avirulent genes AvrPi1, AvrPita2, AvrPi2, and AvrPish in all strains was medium, and the occurrence frequency of avirulent genes AvrPii, AvrPik-p, and AvrPiz in all strains was lower.