[Objective] The aim was to select suitable gene for Chlorella identification and to identify the oil-producing microalgae. [Method] Four candidate gene sequences, the nuclear genomic rDNA of the 18S rRNA gene, internal transcribed spacer (ITS), internal transcribed spacer Ⅱ (ITS Ⅱ ) and the chloroplast rbcL gene, were selected for Chlorella molecular identification. Through these four candidate genes, the genetic variability and distinguish ability between intra-species and inter-species was analyzed to choose the right genes for identification of the high oil-content Chlorella. On this basis, application of these gene segments were classified and identified for five fresh-water isolated Chlorella, which oil-content is more than 30%. [Result] ITS gene was a suitable gene because of its high variation and short fragment length, meanwhile its genetic distance intra-species (0.439 6 ± 0.135 9) was larger than inter-species (0.045 7 ± 0.084 3). Its sequence length varied between different species whereas highly conserved in the same species. By the application of ITS sequences, respectively, five high oil-content stains were identified as one C. Vulgaris, two strains of C. Sorokiniana and two strains of algae Chlorella sp. [ Conclusion] This study had provided reference for the establishment of identification gene pool of Chlorella.%[目的]选择合适的小球藻种属鉴定基因,对高产油微藻进行分子鉴定.[方法]从分子鉴定常用的4条基因[核基因组rDNA的18S,rRNA gene、内转录间隔区(TTS)、内转录间隔区2(ITS-2)和叶绿体rbcL基因]中筛选出最为适用的小球藻鉴定基因,并对从自然水体中分离筛选出的5株油脂含量在30％以上的小球藻(Chlorella sp.)进行了分类鉴定.[结果]ITS序列变异程度高,片段长度短,序列长度在种间变异较大,而在小球藻种内高度保守,且种间距离(0.439 6±0.135 9)远大于种内距离(0.045 7±0.084 3),适用于小球藻属内种的鉴定.应用ITS序列分别将5株高产油藻鉴定为1株C.uulgaris、2株C.sorokiniana藻和2株Chlorella sp..[结论]为建立藻类的鉴定基因库提供了参考.
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