采用PCR-RFLP和RAPD对球壳孢目真菌系统学的研究

对球壳孢目真菌首次采用ＰＣＲ－ＲＦＬＰ和ＲＡＰＤ进行了系统发育研究。以ＩＴＳ１和ＩＴＳ４为引物对４属１２种２４个菌株的核糖体ＤＮＡ转录间区（ＩＴＳ）进行了ＰＣＲ扩增，４种内切酶（ＡｌｕＩ，Ｈｈａ，ＭｓｐＩ，ＴａｑＩ）酶切，结果表明：主要属的ＩＴＳ区长度不同，同属不同种相同。Ｃｏｎｉｏｔｈｙｒｉｕｍ，Ｐｈｙｌｏｓｔｉｃｔａ，Ａｓｃｏｃｈｙｔａ，ＳｅｐｔｏｒｉａＩＴＳ区长度分别为６３０，５６０，５５０，５４０ｂｐ；酶切图谱属间差别明显，属内种间基本一致，暗示传统的分种可能过细，某些种的成立还有商榷的余地，ＰＣＲ－ＲＦＬＰ对确定疑难种属的地位有重要的意义。３属８种１６个菌株的ＲＡＰＤ结果表明，种内图谱相同或图谱类型相同，而种间明显不同，揭示出过去所划分的种的确存在本质的差别，但是否达到种级的差别还有待于进一步研究

SYSTEMATIC STUDIES ON SPHAEROPSIDALES BY USING PCR-RFLP AND RAPD ANALYSIS

PCR-RFLP and RAPD were used to study the systematic relationships among species and genera in Sphaeropsidales for the first time. 24 strains representing 12 species of 4 genera were evaluated by using PCR-RFLP analysis. ITS was amplified and digested with four base restriction enzymes (Alu I, Hha, Msp I, Taq I). The results showed that the length of ITS varied among genera ranging from 540 to 630 bp: Coniothyrium 630 bp, Phyllosticta 560bp, Ascochyta 550bp, Septoria 540 bp. However, the ITS length of each species in the same genus was identical. The restriction digestion patterns were distinctly different among genera, but basically identical among species within the same genus, suggesting that the traditional division for species was perhaps too narrow, and the erection of some species was questionable,PCR-RFLP is useful to identification of uncertain genus. 16 strains of 8 species from 3 genera were amplified with arbitrary primers. The results showed that the patterns were basically identical intraspecifically, but variable interspecifically. This indicates there are genetic differences among species erected previously by traditional criteria.However, whether the differences are distinct enough to separate them at species level needs further study.