小檗在我国北方燕麦秆锈菌有性生殖及病害发生中的作用研究

Puccinia graminis f. sp. avenae (Pga) is a highly specic and parasitic fungus, severely affects oats production. At present, cultivation and distribution of oats in the northern China have been expanding, and oat stem rust became severe as well. Stem rust requires a relatively high temperature, but the main oats cultivation area is located in the northern China where temperature is relatively low, implying that oats stem rust needs the alternate host to provide the primary source. Berberis has been known to be the alternate host for wheat strip rust and stem rust; however, it is not clear yet whether Pga from Berberis can be the initial fungal source for oats stem rust, and virulence variability and race diversity of Pga occur during its sexual reproduction process on Berberis. For these reasons following issues will be addressed: 1. Oat stem rust occurrence in the northern China oat producing areas and rust on Berberis in the surrounding are will be investigated, as well as correlation of the structure and virulence will be examined using the complete analytical host population; 2. The P. graminis collected from Berberis will be identified using different susceptible hosts of triticeae crops and analyzed using the molecular tools for the species of Berberis of the alternate hosts of Pga, as well as the feature and genetic diversity of different Pga from the Berberis; 3. The Pga race identified will be inoculated to oat-Berberis circularly to analyze the virulence variation of Pga after its sexual reproduction on Berberis. These results will provide useful information for control of oats stem rust population and disease.

燕麦秆锈菌是高度专化的专性寄生菌，对燕麦产量造成严重影响。当前，北方燕麦栽培面积和分布范围不断扩大，随之燕麦秆锈病也不断加重。秆锈病是高温病害，但我国燕麦的主栽区主要分布在北方冷凉地区，揭示燕麦秆锈病可能需要转主寄主为其发生提供初菌源。小檗已报道可作为小麦条锈菌和秆锈菌的转主寄主，但小檗上的锈菌能否作为燕麦秆锈病的初菌源以及该菌在小檗上产生的有性生殖对病菌毒力变异和小种多样化的影响尚不清楚。据此，本项目拟开展以下研究：1. 调查我国北方燕麦主产区燕麦秆锈菌以及周边小檗上锈菌的发生情况，并利用完整的鉴别寄主系统分析种群结构和毒力变异情况；2. 用麦类不同属的感病寄主和分子检测方法对小檗上的锈菌进行鉴定，明确可作为燕麦秆锈菌转主寄主的小檗种类、小檗上锈菌的特点和遗传差异；3. 进行燕麦-小檗循环接种，分析经小檗上有性生殖后病菌毒力变异情况。该研究成果将为燕麦秆锈病的流行和防控提供理论依据。

燕麦秆锈菌（Puccinia graminis f. sp. avenae）是高度专化的专性寄生菌，对燕麦产量造成严重影响。当前，北方燕麦栽培面积和分布范围不断扩大，随之燕麦秆锈病也不断加重。秆锈病是高温病害，但我国燕麦的主栽区主要分布在北方冷凉地区，揭示燕麦秆锈病可能需要转主寄主为其发生提供初菌源。小檗已报道可作为小麦条锈菌和秆锈菌的转主寄主，但小檗上的锈菌能否作为燕麦秆锈病的初菌源以及该菌在小檗上产生的有性生殖对病菌毒力变异和小种多样化的影响尚不清楚。据此，本项目通过调查我国北方燕麦主产区燕麦秆锈菌以及周边小檗上锈菌的发生情况，初步确定辽宁、吉林和河北3省存在的主要小檗种类有直穗小檗（Berberis dasystachya）、大叶小檗或异名黄芦木（B. amurensis）和细叶小檗（B. poiretii）3种，进一步通过鉴别寄主鉴定体系及分子生物学技术证实这3种小檗不能作为燕麦秆锈菌的转主寄主，尚不能为燕麦秆锈病的发生提供初菌源；通过对北方燕麦秆锈病调查、标样鉴定及品种抗性分析，明确了当前我国燕麦秆锈菌种群结构和毒力变异情况及品种抗性水平，首次鉴定出TJD、TJN、TKD、TGD、TJB、TJL、SJD和TBD等8个新的燕麦秆锈菌生理小种，证实了Pg6和Pg15基因和坝燕1号对当前国内所有燕麦秆锈菌表现良好抗性，研究结果为我国燕麦抗病育种提供抗理论依据。此外，开展了禾柄锈菌（Puccinia graminis）引起的小麦秆锈病的相关研究工作：完成了历年小麦秆锈菌种群动态和毒力变异监测，为小麦秆锈病的抗病育种提供了理论基础；完成了小麦秆锈病主要流行区域小麦品种抗性及抗病基因的分布布局图，为病害的防控提供指导信息。