小球藻鉴定基因的筛选及高产油微藻的分子鉴定

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（ITS）、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（Chlorellasp.）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.vulgaris、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。

Screening of the Gene for Chlorella Identification and Identification of Oil-producing Microalgae

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.