木耳属真菌rDNA特异性扩增片段的RFLP研究*

对木耳属8个种25个菌株的ITS和28SrDNA5’端两个区域分别进行了PCR扩增和限制酶切片段长度多态性（RFLP）研究。ITS－RFMP研究结果表明，HaeⅢ可将黑木耳与其它种区分开，MspⅠ可将盾形木耳、角质木耳、琥珀木耳和黑木耳4个种区分开，而供试的HaeⅢ、TaqⅠ、HinfⅠ和MaPⅠ这四种限制酶均不能将皱木耳、大木耳、网脉木耳及毛木耳4个种区分开，表明它们之间的亲缘关系较近；结果还表明，ITS—rDNA拷贝在毛木耳和琥珀木耳种内是异质性的，而在黑木耳种内是同质性的。285rDNA-RFLP研究结果表明，供试的4种限制酶中，仅MspⅠ可将盾形木耳和角质木耳区分开，而不能将其它种区分开，这显示了28SrDNA序列在木耳属不同种间的保守性。

RFLP ANALYSIS OF AMPLIFIED NUCLEAR RIBOSOMAL DNA IN THE GENUS AURICULARIA

Internal transcribed spacers(ITS) and 5-end of 285 rDNA were separately amplified via the PCR from twenty-five strains of eight species in Auricularia and subjected to restrichon fragment length polymorphism analysis. The ITS-RFLP resultS showed that Hae III could distinguish A. auricula from the other species, and Msp I could be used to differentiate A.peltata, A.cornea, A.fuscovuccinea and A. auricula. The other four species, A. delicata, A. malaya, A. reticulala and A. polytricha, could not be separated by any of four tested restrichon enzymes Hae ill, Taq i, Hinfl and Msp 1. ms suggested that they were closely related. ITS-RFLP results also suggested that rDNA cOPies of ITS were heterogeneous widen A. polytricha and A.fuscowsuccinea, but homogeneous within A.auricula. 285 rDNA-RFLP results showed that among four testod enzymes, only Msp I could dishnginsh A. peltata from A. cornea. The other species could not be dishngushed by any of the four enzymes. This suggested that the sequences of 285 rDNA were more conserved among different species in the genus Auricularia.