Genetic Diversity In Inonotus Obliquus Revealed By ISSR Analysis

In this paper,21Inonotus obliquus strains from different countries and areas were compared in biological characteristics and polysaccharide productions of mycelia, and analyzed through ISSR to ascertain the genetic differences among Inonotus obliquus strains. Here are the main results.1.mycelium biological characters of Inonotus obliquus strains from different countries and regions are quite different,but the Inonotus obliquus strains from the same area are much closer;mycelium polysaccharide yield of Inonotus obliquus strain JL03reaches7.68g,significantly higher than other strains.2. The DNA of Inonotus obliquus strains were extracted successfully by improved CTAB method. The main components in ISSR-PCR system were screened, then the thermal cycle parameters were optimized, and finally we confirmed the optimal ISSR-PCR system. The concentration of DNA templates was10ng, dNTPs100μmol·L-1, the primer25pmol-L-1, Taq DNA polymerase0.5U, Mg2+1.4mmol·L-1, lO×buffer2.5μ1, and the test were complemented by ddH2O. And the amplification procedures were:5min at94℃, followed by30cycles of1min at94℃,1min at45℃-51℃(depended on the primers),1min at72℃, and last extension at72℃for5min.3. In this study, finger-print analysis was conducted on21Inonotus obliquus stains with11primers, and183DNA bands were amplified,of which169bands were polymorphic with a high polynum of92.3%. The cluster analysis indicated that all the tested strains can be distinguished from each other by using ISSR markers, and the genetic similarity coefficients of the strains was from0.605to0.880.21Inonotus obliquus strains were divided into6groups while the similarity was0.763, showing a strong relevance to the geographical distribution.4. Biological characteristics and polysaccharide productions of Inonotus obliquus mycelia from different countries were compared through cluster analysis. The results based on5biological characteristics as impact factors showed a strong relevance with geographical distributions, indicating the accordance between biological characteristic and geographical similarity. Results based on polysaccharide productions as impact factors displayed no significant differences from geographical distributions.In conclusion,21Inonotus obliquus strains showed notable differences on both biological characteristics and DNA levels, of which the analysis results were about the same, showing a strong correlation with geographical distributions. The polysaccharide productions of different strains were obviously different, but didn’t suggest clear geographic isolations.