16种支孢随机扩增 DNA多态性研究

目的 了解支孢属腐生真菌与致病真菌的基因学特征及二者的关系。方法 采用溴苯提取法提取基因组DNA，以随机扩增DNA多态性法对16种支孢26株菌的DNA指纹图谱作了分析。结果 （1）共选用10个随机引物进行扩增，筛选出2个具有稳定，清晰DNA扩增带型的引物，即引物2：5′-AGGGTCCTCC-3′，引物5：5′-CAGCACCCAC-3′。（2）26株菌DNA带型不完全相同，有一定的种间和种内的遗传变异性，遗传相似性约为37.4%，（3）同种菌具有较高的遗传相似性。（4）部分腐生菌与致病菌位于同一树组中。结论 随机扩增DNA多态性法研究发现支孢属内各种间有一定的遗传相似性。但腐生菌与致病菌的DNA带型性差异。

Characterization of 16 Cladosporium Species by Random Amplification of Polymorphic DNA Assay

Objective To investigate the DNA polymorphism of saprophytes and pathogenicity of Cladosporium species and to find out the relationship between them.Methods The total DNA was extracted with benzyl bromide.Random amplification of polymorphic DNA(RAPD)assay was used to study the finger-printing of 26strains from 16specie s.Results Of ten random primers used,two (primer 2,5)gave good reaction.The sequences of them were:primer 2:5' -AGCGTCCTCC -3',prime r 5:5' -CAGCACCCAC -3'.There were some degrees of variation in RAPD patterns of 26isolates,with interspecies and intraspecies varia-tion.Genetic similarity of 26strains was about 37.4%.The isolates of th e same species showed high genetic similarities.Some saprophytes loc ated in the same group of dendrogram o f Cladosporium species with human -pathogenicity.Conclusion There are some genetic similarities between different species and strains,but no distinct characteristics are found between saprophytes and human -path ogens.