香蘑属DNA条形码的研究

发布时间：2018-04-24 12:36

本文选题：口蘑科 + 香蘑属　；参考：《沈阳农业大学》2017年硕士论文

【摘要】：香蘑属隶属于担子菌门,伞菌目,口蘑科,是一类担子果口蘑状,孢子表面粗糙为主要特征的真菌类群。香蘑属大部分种类具有十分重要的经济价值和药用价值。目前香蘑属与口蘑属、杯伞属和金钱菌属之间的形态特征差异不显著,单纯依靠形态特征难以准确反映物种生物学上的真实性和物种间的亲缘关系,常常造成人为的鉴定错误。因此,寻找更为准确的鉴定方法十分必要,DNA条形码技术是当下比较好的一个解决途径。以香蘑属下7个种共85份材料作为供试标本,选择在真菌物种鉴定或者系统发育分析研究中常用的基因片段 rDNA-ITS、nrDNA-LSU、nrDNA-IGS、EF1-α、RPB2、RPB1以及mtSSU作为候选基因,使用真核生物通用引物进行扩增、测序,筛选该属的DNA条形码。将种内与种间遗传距离差异、序列获得难易程度(PCR和测序成功率),物种辨别能力等三个方面作为评价指标。结果表明ITS种间变异大而在种内相对保守,有明显的Barcoding gap,序列易扩增和测序,能够准确的对香蘑属内种进行区别。故而建议将ITS作为最适宜香蘑属的DNA条形码。本研究结合GenBank中香蘑属物种ITS基因序列,构建了香蘑属的系统发育树,对香蘑属内种的系统发育关系进行了分析。结果发现香蘑属为多系类群,共分为了四个不同的分支,子实体的色调、孢子大小与孢子表面的小疣数量是香蘑属种类鉴定的重要依据。花脸香蘑是一个多系类群。这些发现对认识中国香蘑属的物种多样性具有重要的科学意义。
[Abstract]:The genus Tricholoma belongs to basidiomycetes, Umbellidae and Tricholoma. It is a kind of fungi which is mainly characterized by matsutake and rough spore surface. Most species of Tricholoma have very important economic value and medicinal value. At present, there is no significant difference between the morphological characteristics of the genus Coprinus and the genera of Tricholoma. Depending solely on the morphological characteristics, it is difficult to accurately reflect the biological authenticity of species and the relationship between species, which often results in artificial identification errors. Therefore, it is necessary to find a more accurate identification method. A total of 85 samples from 7 species of Tricholoma comatus were selected as candidate genes, rDNA-ITSnDNA-LSUnrDNA-LSUnrDNA-EGF1- 伪 RPB2RPB1 and mtSSU as candidate genes, and were amplified and sequenced by using universal primers of eukaryotes. The DNA bar code of this genus was screened. The genetic distance difference between species and species, the degree of difficulty of sequence acquisition, the success rate of sequencing and the ability of species discrimination were used as evaluation indexes. The results showed that ITS had great interspecific variation and was relatively conserved within species, with obvious Barcoding gaps.The sequence was easy to be amplified and sequenced, which could distinguish the species of Tricholoma accurately. Therefore, it is suggested that ITS be the most suitable DNA bar code for the genus Tricholoma. In this study, the phylogenetic tree of Tricholoma was constructed based on the ITS gene sequence of Tricholoma species in GenBank, and the phylogenetic relationship of Tricholoma species was analyzed. The results showed that Tricholoma is a multi-lineage group, which is divided into four branches. The color of fruiting body, the size of spores and the quantity of verruca on the surface of spores are the important basis for species identification. Flower-faced mushroom is a multi-lineage group. These findings are of great scientific significance in understanding the species diversity of Tricholoma in China.
【学位授予单位】：沈阳农业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S646

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