黑木耳18S rDNA序列变异及遗传多样性分析

Analyses of Sequence Variation and Genetic Diversity on 18S rDNA Regions of Auricularia auricula-judae

以黑木耳为试材,利用PCR技术扩增黑木耳18S rDNA序列并测序,再用生物软件Clustalx 2、MEGA 5.1对测序结果进行分析和RNA二级结构预测。根据18S rDNA序列多样性分析和预测的二级结构,研究来自中国东北的5个黑木耳栽培菌株的遗传多样性,以便为黑木耳栽培引种和新品种选育提供参考。结果表明：扩增的18S rDNA序列长度约为1 700bp,去除两端测序质量不好的区域后长度为1 695bp,GC含量为48.02%-48.32%,其核苷酸变异位点25个,信息位点10个,变异位点主要集中在88-107bp区域,N-J系统进化树中5个黑木耳聚为一支,毛木耳单独聚另一支,18S rDNA序列分支与传统的分类结果基本一致;18S rDNA区序列一、二级结构相结合可为黑木耳分类鉴定提供相关的分子结构信息。

Used PCR method to amplify 18S rDNA regions of Auricularia auricula-judaes and sequenced them,and then used Clustalx 2,MEGA 5.0software to analyze sequenced results and predicte RNA secondary structure.These results revealed the genetic diversity of five Auricularia auricula-judaes form Northeast China in order to provide reference for cultivation introduction and new variety breeding.The results showed the length of amplification regions was 1 700bp.After removed ends of the poor quality area,the length of 18S rDNA sequences was 1 695bp.The contents of（G＋C）were 48.02-48.32%.There were 25 variable sites and 10 parsimony-informative sites in the whole anaylzed sequence.The variable sites mainly concentrated in 88-107bp.The phylogenetic tree（N-J）showed 5 Auricularia auricula-judaes clustered into a branch,and Auricularia polytricha gathered in another.The 18S rDNA regions homology of Auricularia was consistent with that of traditional taxonomy.Nucleotide sequence combined with secondary structure of 18S rDNA region may be provide some molecular structure information for the classification of Auricularia auricular-judaes.