4株沙漠土壤衣藻的分离培养及形态和分子鉴定

摘要

To study microalgae species of Gurbantunggut Desert and Takilimakan Desert,this experiment isolated four desert microalgae from the sand samples by using the method of 96-well plate limited dilution and spread plate method,and studied the morphology and phylogeny in a polyphasic approach.Morphologically,the investigated strains could be discriminated in Chlorophyta,Volvocales,Chlamydomonadaceae.The morphological differences were reflected in the four distinct species.The GTD2A2 strain had very high similarity of 99.92％ to Chlamydomonas debaryana (FR865608.1),which demonstrated that GTD2A2 strains were identified to species.The 18S rDNA gene sequences of GTD3a-5,GTD4C,and TLD7a-2 strain were 98.10 ％,98.69％ and 97.65％ similar to Chlamydomonas baca (FR865613.1),C.reinhardtii (M32703.1)and Chlamydomonas sp.(FR865563.1),which demonstrated that GTD3a-5,GTD4C,GTD7A-2 strains were identified to genus.This study clearly defines the taxonomic status of 4 strains of desert Chlamydomonas and Chlamydomonas with other relatives,providing a valuable foundation for further study of desert algae in the molecular biology and physiology.%从古尔班通古特沙漠和塔克拉玛干沙漠采集沙样,先进行混合培养,混培藻液采用96孔板有限稀释法和平板法,分离到4株微藻(GTD2A,GTD4C,TLD7A-2,3a-5),采用传统形态鉴定方法及18S rDNA片段克隆分别对筛选的4株微藻进行鉴定,并进行系统发育分析.结果表明:通过形态学特征将4株藻初步鉴定为绿藻门、绿藻纲、团藻目、衣藻科.采用分子生物学方法克隆的18S rDNA片段进行复核的结果表明GTD2A2与GenBank数据库中的Chlamydomonas debaryana(FR865608.1)同源性达到了99.92％,说明已经鉴定至种.GTD3a-5、GTD4C、TLD7a-2与GenBank数据库中Chlamydomonas baca(FR865613.1)、C.reinhardtii和Chlamydomonas sp.(FR865563.1)3个藻种的同源性分别达到了98.10％、98.69％和97.65％.研究确定了4株沙漠衣藻的分类地位及其同其它衣藻种的亲源关系,为以后的研究沙漠藻的分子生物学和生理学研究奠定了基础.