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大豆胞囊线虫Heteroderaglycines(SCN)广泛分布于亚洲和美洲,在中国和美洲被认为大豆主要病害。SCN从遗传上讲不是纯的,并且可以在短时间内克服大豆的抗性,在此研究中,应用了被认为具有较大变异的遗传区域—内转录间隔区(包括5.8S、ITS1和ITS2),来分析中国和美洲的美国、加拿大、阿根廷SCN群体的种内变化。本试验在大豆田中采集16个SCN样品用于测定,所有样品收集后在温室大豆感病品种Essex上进行繁殖,获取卵和二龄幼虫,进行DNA提取,用PCR扩增ITS片段之后,用17种限制性内切酶来酶切PCR产物,共产生25条酶切片段。其中Xba,BamHⅠ,HindⅡ,HindⅢ,SstⅠ,XhoⅠ,NcoⅠ和SacⅠ8种限制性内切酶没能切开SCN群体的rDNA-ITS的PCR扩增产物。用AvaⅠ,EcoRⅠ,HinfⅠ,AluⅠ,HaeⅢ,ClaⅠ,MboⅠ,AccⅠ和RsaⅠ9种限制性内切酶酶切SCN群体的rDNA-ITS的PCR扩增产物后都得到了2个以上的RFLP片断;用限制性内切酶AluⅠ,EcoRⅠ,HinfⅠ,HaeⅢ,ClaⅠ,MboⅠ,AccⅠ和RsaⅠ酶切所有的SCN群体的rDNA-ITS的PCR扩增产物都分别得到了相同的RFLP片断,只有AvaI酶切SCN群体的rDNA-ITS的PCR扩增产物后产生了多态性。中国SCN用AvaI酶切后,产生3条片段,而中国以外的美洲(美国、加拿大、阿根廷)的11个SCN均产生2条片段。此结果显示中国SCN群与美洲
Heteroderalycines (SCN) are widely distributed in Asia and the Americas, and are considered as the major soybean diseases in China and the Americas. SCN is not genetically pure and can overcome soybean resistance in a short period of time. In this study, the genetic regions considered to have large variation - the internal transcribed spacer region (including 5.8S, ITS1 and ITS2 ) To analyze intraspecific changes in the SCN population in China, the Americas, the United States, Canada and Argentina. In this experiment, 16 SCN samples were collected for determination in soybean field. All the samples were collected and propagated on greenhouse soybean susceptible cultivar Essex. Egg and second instar larvae were obtained for DNA extraction. ITS fragment was amplified by PCR, Restriction enzyme digestion of PCR products, a total of 25 enzyme-generated fragments. Among them, Xba, BamHI, HindII, HindIII, SstI, XhoI, NcoI and SacI restriction endonucleases failed to excise the PCR amplification products of rDNA-ITS of SCN population. Two or more RFLP fragments were obtained after PCR amplification of rDNA-ITS of SCN population by restriction endonuclease digestion with AvaⅠ, EcoRⅠ, HinfⅠ, AluⅠ, HaeⅢ, ClaⅠ, MboⅠ, AccⅠand RsaⅠ; The restriction endonucleases AluI, EcoRI, HinfI, HaeIII, ClaI, MboI, AccI and RsaI digested all the SCN population of rDNA-ITS PCR products were obtained the same RFLP fragment, only AvaI cut SCN population The rDNA-ITS PCR products produced polymorphisms. After SCN digestion with AvaI in China, three fragments were produced, while 11 SCNs in the Americas (USA, Canada, Argentina) outside China produced two fragments. This result shows that China SCN group and the Americas