利用RAPD技术评估金针菇种质资源

Evalution of Germplasm Resources of Flammulina velutipes with RAPD Technique

本文利用20个10核苷酸的随机引物对来源不同而具有代表性的16个金针菇菌株进行了RAPD分析研究。结果表明:所测试的20个随机引物中有6个引物的扩增产物DNA片断表现出明显的多态性,对所有供测试的金针菇菌株总共扩增出84条具重复性的DNA片断;同时也显示供试的16个金针菇菌株两两间的遗传相似性变化较大(相似系数从0.0592到0.8000)。另外,采用系统聚类法中的类平均法,对供试的16个菌株两两间的相似系数进行聚类,可将它们分为四大类,各大类的类间和类内菌株的遗传变异程度较大,其中以Ⅳ类内各菌株间的最高(平均相似系数为0.4353),Ⅰ类和Ⅱ类间各菌株间的最低(平均相似系数为0.6812)。但是,从整个被测试的16个金针菇菌株来看,它们之间的遗传变异并不丰富(总平均相似系数为0.5292)。同时,将RAPD技术应用于不同菌株间遗传差异的研究,具有反应迅速、不受外界环境条件影响、能从DNA分子水平上揭示菌株间的遗传差异等优点。因此,RAPD分析技术是一种快速准确评估食用菌种质资源的有效方法。

In this paper, the random amplified polymorphic DNA (RAPD) analysis was conducted with 20 ten-nucleotide random primers in 16 representative strains of Flammulina velutipes collected from various localities. The results revealed that six out of the twenty random primers were scorable polymorphic ones. In total, eighty-four band positions were scored(l/0) for all of the tested strains. Meanwhile, genetic similarity between each of all the tested strains of Flammulina velutipes differed widely with the coefficient of similarity ranged from 0.0952 to 0.8000. On the other hand, cluster analysis based on the coefficient of genetic similarity between the tested strains of Flammulina velutipes was carried out by UPGMA and the 16 tested strains of Flammulina velutipes were subdivided into four groups. There were various degrees of genetic diversity between strains of intra-groups and inter-groups. And it was found that the degree of genetic diversity between strains of group IV with an average similarity coefficient of 0.4353 was the highest in all groups, and that the degree of genetic diversity between strains in group I and group n with an average similarity coefficient of 0.6812 was the lowest. However, in terms of all the strains tested the degree of genetic variability as a whole was not so significant because a total average similarity coefficient was only 0.5259. Meanwhile, the application of RAPD technique in studying genetic differences between various strains had a lot of advantages such as reacting fast, not being influenced by outer environment and showing genetic diversity among strains on the level of DNA molecule. Therefore, RAPD analysis technique might be ascribed as one of the most effective methods to evalute germplasm resources rapidly.