【作者】 刘友勋；

【导师】 成国英；

【作者基本信息】 华中农业大学 ， 植物病理学， 2003， 硕士

【摘要】 以针刺接种法，研究了20个水稻品种与40株稻细条病菌的互作关系。通过对品种的抗感性和生育性的比较，选出金刚30、窄叶青、XM5、XM6、M41作为鉴别品种，以此为基础，40株稻细条病菌被划分成0、Ⅰ、Ⅱ、Ⅲ、Ⅳ、Ⅴ、Ⅵ等7个型，与浙江、广东、湖南所用鉴别品种的鉴别性相比较，此套鉴别品种可以鉴别出病菌毒力呈强弱性反应的数量变化和呈互作交叉性反应的质量变化。 以金刚30、窄叶青、XM5、XM6、M41等5个品种为鉴别品种，将来自4省的75个细条病菌菌株的毒力划分为0、Ⅰ、Ⅱ、Ⅲ、Ⅳ、Ⅴ、Ⅵ等7个致病型，各型在鉴别品种上的反应依次为RRRRR、SRRRR、SSRRR、SSSRR、SSSSR、SSRSR、SRSRR。0、Ⅰ、Ⅱ、Ⅲ、Ⅳ型毒力差异主要呈由弱到强的数量变化，Ⅴ和Ⅵ型间呈强互作反应。各型菌所占比例：0型5.3％、Ⅰ型9.3％、Ⅱ型20％、Ⅲ型44％、Ⅳ型10.7％、Ⅴ型6.7％、Ⅵ型4％；4省菌株毒力的初步比较表明，福建、江西以Ⅲ、Ⅳ型菌为主，依次占参试菌的88％、50％；湖北以Ⅱ、Ⅲ型菌为主，占参试菌的70％；湖南没表现突出的优势群，但较强毒力的Ⅱ、Ⅲ、Ⅳ型菌所占比例为55.6％；湖北省内不同稻区，病菌毒力也不尽相同。 在金刚30、窄叶青、XM5、XM6、M41等5个品种上，对冰箱保存的水稻细条病菌0型菌RHL1-2、Ⅱ型菌RJ3-2、Ⅲ型菌RJX3-2、Ⅳ型菌RH2-2(母菌)和它们的单细胞系的致病力进行了比较，结果表明：0型菌RHL1-2和它的9个单细胞系都表现为0型；Ⅱ型菌RJ3-2致病力降为了0型，它的9个单细胞系也都表现为0型；Ⅲ型菌RJX3-2降为了Ⅱ型，其单细胞系中，1个Ⅰ型，3个Ⅱ型，5个Ⅲ型；Ⅳ型菌RH2-2致病力降为了Ⅱ型，其单细胞系中，4个0型，1个Ⅰ型，2个Ⅱ型，1个Ⅲ型，1个Ⅵ型；用新复极差法测定Ⅲ型菌RJX3-2、Ⅳ型菌RH2-2的单细胞系在品种金刚30、窄叶青、XM5上的毒力，均有显著差异；说明，从病叶上分离的原始菌株一定是由不同毒力的单细胞系组成的混合体，在冰箱保存期间，不同毒力的单细胞系的存活率不同，导致活化后的母株的单细胞系组成比发生变化，从而使致病力发生了改变。 采用引物BOX和ERIC对来自4省的35个细条病菌菌株进行Rep-PCR扩增，BOX引物扩增出14条指纹带，10种谱型，以致病型为单位计算遗传多样性值为0.63～1.00；ERIC引物扩增出19条指纹带，17种谱型，遗传多样性值为0.86～1，可见引物ERIC比BOX在遗传多样性方面有更好的分辨率；树状聚类图中反映的遗传分簇差异，与菌株的致病型及其地理的来源之间没有相关性。 用BOX或ERIC为引物对4个母株和它们的36个单细胞进行PCR扩增，结果表明，同一母株的单细胞系之间，存在遗传差异，‘不同母株的单细胞系的遗传差异程度不同。在ERIC一PCR聚类图中，RJX3一2和其单细胞系之间的异源率达到27.3%水平，说明母株一定是含不同单细胞系的混合体。但这种差异与菌株的毒力分化无明显相关性。更多还原

【Abstract】 By the pin prick method of inoculation, the interaction of 20 rice varieties and 40 strains of Xanthomonas oryzae pv. oryzicola(Xoo) were studied. According to resistance susceptibility and period of growth of these rice cultivars, Jingang30 Zhaiyeqing XM5 XM6 M41 were selected as differential host from 20 rice varieties and 40 strains were classified into seven pathotypes 0, I , II, III, IV, V , VI . Compared with the differential host from Zhejiang,Hunan and Guangdong, the differentials screened by this test could differentiate the quantity variation from weak to strong and the quality variation of cross interaction of virulence of these strainsThe pathogenicity of 75 isolates of Xanthomonas oryzae pv. oryzicola(Xoo) from the provinces of Hubei, Hunan, Jiangxi, Fujian was tested on 5 differential varieties of Jingang 30, zheyeqing,Xm5, Xm6 and M41. It was classified into seven pathotypes of 0, I, IK III, IV. V, VI with reaction patterns of RRRRR, SRRRR, SSRRR, SSSRR, SSSSR, SSRSR, SRSRR. The virulence of 0, I , IK III, IV represented as quantity variation from weak to strong and there was quality variation with cross interaction between V and VI. The proportion of 0, I , IK HI, IV, V, VI was 5.3%, 9.3%, 20%, 44%, 10.7%, 6.7%, 4% respectively. The result indicated that the predominant pathotype was III and IVin Fujian and Jianxi, the proportion of which was 88%, 50% in turn; II and III in Hubei, the proportion was 70%; no predominant pathotype in Hunan but the sum of proportion of II, III, IV was 55.6% comparing the pathogenicity of Xoc from four provinces.It was comparied on 5 differential varieties of Jingang30, Zhaiyeqing, XM5, XM6, M41 that the virulence of strain RHL1-2 (pathotype 0), RJ3-2 (pathotype II) , RJX3-2 (pathotypeIII) , RH2-2 (pathotypeIV) and their 39 mono-cell clones(MCC ). The result showed that virulent pattern of RHL1-2 and its MCC was pathotype 0; RJ3-2 and its MCC fell into pathotype 0; RJX3-2 fell into pathotype II ,one of its MCC represented pathotype I , three did pathotype II, five did pathotypelll; RJX3-2 fell into II, four of its MCC represented 0, one did I, two did II, one did III and one did D. There was significant difference among the virulence of RJX3-2, RH2-2 and their MCC on Jingang30, Zhaiyeqing and XM5 tested By SSR (Duncan). The results suggested that the original strains isolated from leaf of rice should be made up of different virulent cells. The virulent variation of mother strains was owed to the changeover of composition of strains.As it was different that the survival rate of different virulent MCC in mother strains after a period of preservation in refrigerator.Rep-PCR was used to analyze the genetic diversity in a population of Xanthomonoas oryzae pv.oryzicola (Xoo) isolated from 4 provinces. Genomic DNA from 35 strains was amplified with two specific primers (BOX and ERIC). 14 bands and 10 patterns of DNA fringer-prints amplified by BOX-PCR. And 19 bands and 17 patterns were got by ERIC-PCR. The range of genetic diversity value was 0.63-1.00 with BOX-PCR and 0.86-1.00 with ERIC-PCR based on pathotypes , which indicated the primer ERIC was better than BOX in estimating the genetic diversity of Xoo. There was no correlation between the pathotypes , geographic source and clusters based on patterns of DNA fringer-prints.Genomic DNA from 4 mother strains and their 36 mono-cell clones(MCC ) was obtained by BOX-PCR and ERIC-PCR. The result showed that there was genetic difference in MCC from the same mother strain or the different strains, but the difference had no correlation with pathogenicity of MCC . The level of difference in MCC from RJX3-2 strain was 27.3% , which proved that the mother strain was composed of different MCC.更多还原