人工栽培蛹虫草退化现象的分子分析*

利用PCR-RFLP和RAPD方法对野生驯化蛹虫草及其退化菌种进行了基因水平的分析。PCR-RFLP实验,采用真菌通用引物ITS1和ITS4,扩增出5.8S和其两端的两个转录间隔区(ITS),选用5种识别四个碱基的内切酶(HaeIII、AfaI、TagI、AluI和XspI),其中只XspI酶切结果在两个菌种中存在差异,进一步测序表明,整个片段全长534bp,共有13个位点发生碱基突变,且都为c转换为t。RAPD实验,选用4组计80个随机引物进行PCR扩增,共筛选出9个对所有供试个体均存在明显差异的引物。结果表明了退化菌株较野生驯化菌株在DNA水平上发生了频率较高的突变,这些突变可能直接与导致菌种退化的基因相关联。

MOLECULAR ANALYSIS OF DEGENERATION OF ARTIFICIAL PLANTED CORDYCEPS MILITARIS

PCR-RFLP and RAPD, were used to study the level of difference in gene of naturalized Cordyceps militaris and its degenerative strain.By using PCR-RFLP, 5.8S and its two ITS region were amplified and digested with five restriction enzymes (HaeⅢ、AfaⅠ、TagⅠ、AluⅠand XspⅠ).The sequencing results showed the length of 5.8S and ITS region is 534bp and there are 13 mutant bases. Of 80 primers,9 ones generated reproducible RAPD profiles. The results showed the degenerative strain gene rated high frequency mutation . The mutation may associate with the gene which resulted in degeneration of the strain .