【作者】 李永娟；

【导师】 朱杰华；

【作者基本信息】 河北农业大学 ， 植物病理学， 2007， 硕士

【摘要】 纹枯病是由丝核菌（Rhizoctonia）真菌引起的小麦、玉米上的一种危害严重的病害，近年来在我国大部分地区均有发生，河北省该病害发生日趋严重，直接影响了小麦、玉米的产量和品质。本研究从河北省十个县市采集纹枯病标样进行研究，旨在明确河北省小麦玉米纹枯病菌群体分布情况及其遗传多样性，为进一步制定该病的综合治理措施提供理论依据。1．对从河北省采集的130株小麦纹枯病菌株和21株玉米纹枯病菌株从形态上鉴定，明确了河北省境内小麦纹枯病的发生主要是双核丝核菌所致，玉米纹枯病的发生主要是多核丝核菌所致。丝核菌生长的最适pH值为6，在PDA培养基上的生长速度大于在玉米粉培养基上的生长速度大于在水琼脂上的生长速度，Fe³⁺、Zn²⁺、Pb²⁺、Mg²⁺、Mn²⁺、Hg²⁺六种金属离子对菌丝生长也有一定的影响。2．通过待测菌株与标准菌株菌丝融合群的测定发现，河北省小麦纹枯病菌主要是CAG-1融合群，占分离到的菌株总数的95.16％；同时在小麦上也分离到了AG-2和WAG融合群；玉米纹枯病菌主要是AG-1-IA和AG-5融合群，占分离到的菌株总数的44.44％和33.33％，同时分离到了AG-1-IC、AG-2和CAG-1融合群。3．通过室内盆栽接种试验，对小麦纹枯病菌株和玉米纹枯病菌株进行了致病力的测定，测定结果表明：丝核菌对原寄主的致病力强于对其它寄主的致病力，即采自小麦上的双核丝核菌CAG-1融合群对小麦的致病力高于对玉米的致病力，采自玉米上的多核丝核菌对玉米的致病力高于对小麦的致病力。同时发现采自不同地区的菌株间致病力有所不同，但大部分菌株间致病力差异不显著。4．在前人工作的基础上，通过对影响AFLP体系建立的关键因素进行探索，建立了适合构建丝核菌DNA指纹图谱的技术体系，为研究丝核菌的遗传变异和构建遗传图谱奠定了坚实的基础。5．利用3对AFLP引物扩增不同地区的30个小麦纹枯病菌株和20个玉米纹枯病菌株，在双核丝核菌中共扩增出144条带，多态性条带为105条，多态率为72.91％；多核丝核菌共扩增出150条带，多态性条带为135条，多态率为90.0％。基于AFLPs多态性带的聚类结果分析表明供试菌株存在着丰富的遗传多样性，且纹枯病菌的DNA多样性与菌株本身的遗传分化（融合群）有一定的相关性，而与病原菌地理来源及致病力无明显相关性。更多还原

【Abstract】 Wheat sharp eyespot and Corn sheath blight were one serious disease caused byRhizoctonia. This kind of disease was occurred often in the wheat and corn growing area inChina. Wheat sharp eyespot and Corn sheath blight was getting more severe in rescentyears in HeiBei province. The yield and quality of wheat and corn are decreased clearlydue to Rhizoctonia infection. Diseased samples were collected from ten counties or citiesin Hebei. The objective was to understand on the population structure and genetic diversityof the pathogen in Hebei. The results will set up a theory foundation for establishing theintegrated management measures of wheat sharp eyespot and corn sheath blight.1. One hundred and thirty isolates of wheat sharp eyespot and twenty-one isolates ofcorn sheath blight collected from Hebei province were identified with morphologicalcharacteristics. The result showed that the wheat sharp eyespot was caused by binuclearRhizoctonia and the corn sheath blight was caused by polynuclear Rhizoctonia in Hebeiprovince. The fittest pH is 6 of Rhizoctonia, and the growth of mycelial on PDA is thequickest, the second is on maize media, the last is on water-agar. Fe³⁺、Zn²⁺、Pb²⁺、Mg²⁺、Mn²⁺、Hg²⁺ have some certain influence on the growing of mycelial.2. All Rhizoctonia isolates from the samples of wheat sharp eyespot and corn sheathblight in Hebei were tested for anastomosis group. The result showed that pathogen ofwheat sharp eyespot belonged to anastomosis group CAG-1, AG2 and WAG, of themCAG-1 with frequency of 95.16% was major anastomosis group. The pathogen of cornsheath blight belonged to anastomosis group AG-1-IA, AG-1-IC, AG-2, AG-5 and CAG-1,in which AG-1-IA and AG-5 with frequency of 44.44% and 33.33% were majoranastomosis group.3. The pathogenicity of some typical isolates was valuated by artificialcross-inoculation. The results showed that the virulence of Rhizoctonia on original hostwas higher than on the other host, the virulence of anastomosis group CAG-1 of binuclearon wheat was higher than it on maize, the virulence of polynuclear on maize was higherthan it on wheat. The result also showed that the virulence of isolates from different areawas different, but there was no significant difference among the pathogenicity of isolates.4. An efficient AFLP DNA fingerprinting protocol for Rhizoctonia was modified. Theimprovement of protocol could facilitate the research on the genotyic diversity, constructing genetic maps of the pathogen.5. Thirty Rhizoctonia isolates of wheat sharp eyespot and twenty Rhizoctonia isolatesof corn sheath blight were amplified with three AFLP primer combinations. A tatal of 144AFLP bands were amplified of binuclear Rhizoctonia, and 105 were polymorphic bands.The rate of polymorphism bands was 72.91%. 150 DNA bands （fingerprints） wereobserved of polynuclear Rhizoctonia, and 145 out of 150 DNA bands were polymorphicones. The rate of polymorphism bands was 90.0%. The result based on the cluster analyseindicated that DNA polymorphism of Rhizoctonia was correlated with genetic variation ofanastomosis group. The DNA polymorphism was not correlated with geographical locationand the pathogenicity of the isolate.更多还原