【作者】 王平；

【导师】 黄云； 何忠全；

【作者基本信息】 四川农业大学 ， 植物病理学， 2007， 硕士

【摘要】 由Magnaporthe grisea(Hebert)Barr．引起的水稻稻瘟病是一种世界性的真菌病害，对世界粮食产量有着重要影响。利用水稻生物多样性控制稻瘟病是近年稻瘟病防治研究的热点与焦点，在四川甚至全国正在进行推广和应用。2005年四川省大面积发生稻瘟病，而在推行杂糯间栽的地区，稻瘟病发生依然严重。为了明确水稻生物多样性——杂糯间栽技术对稻瘟病的影响，本研究对杂糯间栽技术控制稻瘟病的效果、杂糯间栽田间稻瘟病菌的种群结构和遗传组成差异、稻瘟病最佳控制效果的病害发生程度阈值比较、品种如何搭配、杂糯间栽田间病原菌种群结构的变化等进行了深入系统的研究．通过在四川省泸州叙永、内江资中、成都蒲江、南充营山、雅安草坝5个点的试验研究，其结果如下：1杂糯间栽在不同生态区不同发病程度下对稻瘟病的控制作用不同。在发病较重的生态区(叙永，发病率86.46％，病指53.61)，间栽糯稻发病程度与净栽糯稻无显著差异。在发病较轻的生态区(营山，发病率6.90％，病指1.08)，部分间栽处理中糯稻发病程度极显著低于净栽。在叙永，杂糯间栽对感病糯稻叶瘟的控制效果在12％～26％之间，对颈瘟的效果为0；在发病较轻的雅安、营山，对叶瘟的控制效果最高达到46％～88％，对糯稻颈瘟控制效果的范围在11％～76％。总体来说，在发病较轻的生态区，杂糯间栽对感病糯稻稻瘟病的控制效果较好。2不同抗性杂交稻品种与糯稻搭配后对稻瘟病的控制作用不同。主栽杂交稻品种的抗性越强，其与糯稻搭配后对糯稻上稻瘟病的控制作用愈明显。当主栽品种为高感病品种时，其与糯稻搭配后对稻瘟病的控制作用与糯稻净栽无显著性差异。3不同间栽模式对稻瘟病的控制效果不同，其中“4+1”和“6+1”模式对稻瘟病的控制最好；“1+1”模式对稻瘟病的控制效果最差，显著低于“4+1”和“6+1”模式。同时，当主栽品种是感病品种时，所有模式的杂糯间栽对稻瘟病的控制效果不理想。4采用国内统一鉴别品种对净栽、间栽田间稻瘟病菌进行小种测定，结果显示净栽、间栽田间稻瘟病菌种群结构差异不明显，都以ZB、ZG种群为主；优势种群ZB群所占比例都在45％左右；ZB群中小种类型最为丰富，净栽、间栽田间稻瘟病菌大部分生理小种类型一致。利用日本13个清泽系列单基因对净栽、间栽田间稻瘟病菌无毒基因的测定，结果显示净栽、间栽田间稻瘟病菌无毒基因类型一致，无毒基因频率差异不明显。采用9个常规种植品种对杂交稻、糯稻上稻瘟病病菌株交互侵染作用的测定，结果显示杂交稻、糯稻上分离稻瘟病菌株能够进行交互侵染，既能够侵染杂交稻又能够侵染糯稻的菌株所占有的比例达到70％～90％。5采用6对SSR引物对净栽、间栽田间稻瘟病菌进行PCR扩增，并进行遗传聚类分析，结果表明：净栽、间栽田间稻瘟病菌遗传组成丰富程度差异不明显。净栽杂交稻上稻瘟病菌遗传组成比净栽糯稻上丰富；净栽杂交稻上与间栽杂交稻上稻瘟病菌遗传组成丰富程度上差异不明显；净栽糯稻上与间栽糯稻上稻瘟病菌之间有差异，但是它们之间优势宗谱都是第Ⅶ宗谱。在净栽、间栽田间都存在优势宗谱，优势宗谱所占的比例出现范围在30％～80％之间；总体上间栽田间稻瘟病菌株优势遗传宗谱所占比例低于净栽。更多还原

【Abstract】 Rice blast, caused by Magnaporthe grisea (Hebert) Barr., is the most devastating fungal disease in the world, and has important effect on the yields. It’s a hotspot and focus to using rice mixture to control the rice blast, and it was generalized and application all the country. An epidemic of rice blast occurred in Sichuan province in 2005, and the rice mixture didn’t control it effectively. In order to find out the effect of rice mixture on rice blast, we studied on the effects of rice mixture on rice blast, and the difference of race composition and genetic structure of Magnaporthe grisea in rice mixture fields and pure-cropping field. The experimentation was carried out in Xuyong, Zizhong, Yinshan, Pujiang, and Yaan County; the main results of this study are as follows.1. The effects of rice mixture on rice blast were different in different ecological zones. There was no significant difference between rice mixture and monoculture in disease severity of rice blast in severe occurrence region, its disease incidence was 86.46% and disease index was 53.61 in Xuyong County. In Yinshan County, its disease incidence was 6.90% and disease index was 1.08, the disease severities of glutinous rice in many of inter-cropping treatments were highly significant lower than pure-cropping treatment. The control effect of rice mixture on leaf blast of glutinous rice was 12% to 26%, and 0% on panicle blast in Xuyong County. The control effect was 46% to 88% on leaf blast and 11% to 76% on panicle blast in Yaan and Yinshan County. In a word, the control effect of rice mixture on rice blast of glutinous rice was higher in lower disease severity plasce.2. The effects of rice mixture planted with different resistance Hybrid varieties on rice blast were different. The higher resistance the main variety has the higher effect of rice mixture has on rice blast of glutinous rice. When the main variety infected seriously rice blast, there is no significant difference in disease severity between glutinous rices in mixture and monoculture fields.3. The effects of rice mixture planted with different modes on rice blast were different. The effective modes of rice mixture were "4+1" and "6+1", and "1+1" mode can not contol rice blast. The effects of "1+1" mode on rice blast was significant lower than "4+1" and "6+1" modes. When the main variety was susceptible, the effects of all the modes on rice blast were low.4. The virulence of these isolates from pure-cropping and inter-cropping fields was assayed with a standard set of 7 differential rice varieties commonly used in China, the results showed that there was no significant difference of M. gresea race composition between rice mixture and monoculture. The dominant groups both were ZB and ZG group. The proportion of ZB group in mixture fields is about 45%, corresponded with ones in monoculture fields. The types of ZB group was abundant than the others, and a majority of races types in mixture fields were the same as ones in monoculture fields. The avirulence gene of these isolates from pure-cropping and inter-cropping fields was assayed with Tsunematru mono-resistance-gene lines from Japan, the results showed that the type of avirulence gene were the same, and there was no significant difference of frequency between mixture and monoculture. The cross infection of M. gresea from pure-cropping and inter-cropping fields was assayed with 9 commonly planted in Sichuan, the results showed that there was cross infection between isolates of M. grisea in mixture and monoculture, the frequencies of cross infection isolates were 70% to 90%.5. The genetic dicersity of M. grisea from pure-cropping and inter-cropping fields was assayed with 6 pair of SSR primers; the results showed that there was no significant difference of genetic structure between mixture and monoculture. And the genetic lineages of M. grisea in pure-cropping hybrid varieties were abundant than ones in pure-cropping glutinous variety. There was no significant difference of genetic structure between pure-cropping hybrid varieties and inter-cropping hybrid varieties. The genetic lineages of M. grisea in inter-cropping glutinous variey were abundant than ones in pure-cropping glutinous variety, but the dominant lineage both were lineageⅦ. There was dominant lineage both in mixture fields and monoculture fields, the frequency of dominant lineage were 30% to 80%, and the frequencies of dominant lineage in mixture fields were lower than ones in monoculture fields.更多还原