【摘要】 用Pot2-rep-PCR方法获得的稻瘟病菌(Magnaporthegrisea)指纹图谱基本反映了中等重复倒位单元Pot2的拷贝数和在基因组中的分布,理论扩增最短片段长度应为1199bp。而在江苏和中国北方来源粳稻菌株中常发现有600bp左右长度的条带。经回收测序该片段P1长度为606bp,其中Pot2-1端384bp命名为S1,与Pot2的对应序列完全同源,Pot2-2端222bp命名为S2,与Pot2对应序列同源性达89.3%。以P1及Pot2引物对可扩增的理论片段范围内的另一新扩增片段P2作为探针分别与10个DNA指纹差异明显并均含606bp片段的菌株PCR产物进行Southern杂交,结果为P1与Pot2rep-PCR产物的每条带均有同源性,而P2与扩增产物的最小条带没有同源性,认为P1片段的产生原因为Pot2片段的部分缺失或者部分片段在基因组中移动后整合到另一个Pot2之前。更多还原

【Abstract】 DNA fingerprints using Pot2-rep-PCR method demonstrated basically copies and distribution of Pot2 in genome of Magnaporthe grisea,and the shortest segment of amplified segments in theory was 1 199 bp.But a band about 600 bp was usually found among Pot2 rep-PCR products of M.grisea isolates in Jiangsu and North of China,which size was 606 bp named P1 after being reclaimed and sequenced.The end of Pot2-1 named S1(384 bp)was homologous to Pot2,another end of Pot2-2 named S2(222 bp)of this band was 89.3% similarity to Pot2.Southern hybridization analysis of 10 isolates showed distinctly different PCR bands,but consisted of the P1 with another segment P2 probe amplified based Pot2 and P1 sequences revealed that every bands of Rot2-rep-PCR products had similarity with P1.It showed that there were similarity of P1 to every band in Pot2 rep-PCR products and no similarity of P2 to the shortest band in Pot2 rep-PCR products.It is the reason of the shortest band 606 bp appearing that a part of Pot2 fragment was deletion or a part of fragment removed and conformed to the front of another Pot2.更多还原