福建省稻瘟病菌生理小种组成及水稻主栽品种的抗性筛选

Physiological Races of Magnaporthe grisea and Disease-Resistant Rice in Fujian

【目的】了解近年来福建省稻瘟病菌生理小种组成和福建省主栽水稻品种的稻瘟病抗性情况,可为合理布局抗病品种和稻瘟病抗性育种提供科学依据。【方法】于2017–2019年收集福建省17个县市(地区)的中稻稻瘟病穗颈瘟样本,分离单孢用7个中国鉴别品种进行分类鉴定,并从中筛选出60个福建省内具有代表性的稻瘟病菌株,室内喷雾接菌32个福建省主栽水稻品种,同时用9个稻瘟病抗性基因分子标记检测这32个主栽品种。【结果】7个鉴别品种的鉴定分类结果显示,稻瘟病生理小种ZA群出现频率为39.48%,为优势种群;用60个代表性生理小种室内接菌鉴定结果显示,这些生理小种平均致病率为23.28%,相对较低,说明福建省推广的主栽水稻品种的抗瘟性相对较好;鉴定筛选出宽抗谱水稻品种15份,其中隆两优华占、两优332的抗谱最广,建议在生产上推广利用。【结论】福建省的稻瘟病生理小种已由早期的以ZB、ZC群为优势种群逐渐转变为以ZA群为优势种群,这与近年来甬优系列品种的大面积推广有关。在抗稻瘟病的品种布局上应优选抗谱宽度大的品种,同时在新品种推广种植中,应追溯宽抗谱水稻品种的致病生理小种来源地,尽量避开可能致使拟推广品种感病的生理小种所在地区。

【Objective】 Physiological races of Magnaporthe grisea, the major pathogen of rice blast disease in Fujian in recent years, and the rice varieties resistant to the infection were studied to understand the fungal distribution and provide a clue for breeding to prevent the disease. 【Method】 Microbial samples from the diseased rice in 17 localities in the province were collected from 2017 to 2019. Monospores were isolated and classified by comparing with 7 species with known identifications. From them, 60 distinctive strains were sprayed indoor on 32 local rice varieties to detect the presence of 9 molecular markers of rice blast resistance genes on the inoculated rice plants. 【Result】 Using the 7 specimens with known identification and classification for comparison, the ZA group with an occurrence frequency at 39.48% was found to be the dominant physiological race of rice blast. Inoculation of the 60 physiological races on the 32 rice varieties showed an average pathogenicity rate of 23.28%. The relatively low infection rate suggested that most of the local rice were blast resistant to varying degrees. Subsequently, 15 of the rice varieties with broad resistance spectra were identified. Of which,Longliangyouhuazhan and Liangyou 332 exhibited the broadest spectra and were considered suitable for further applications.【Conclusion】 The dominant physiological race of M. grisea appeared to have gradually changed over recent years from ZB and ZC to ZA group in Fujian. The transformation might relate to the large-scale promotion of the Yongyou rice series during the time. Consequently, it would be prudent in selecting rice varieties with a broad-spectrum on blast resistance for promotion.And, prior to introducing a new variety, an understanding of the origin of pathogenic physiological races would be necessary to preclude areas that are susceptible to the spread of the disease for the cultivation.