摘要
通过基因克隆和序列测定，获得了地木耳、发菜和葛仙米的16S rRNA序列。以集胞藻为外类群，采用邻接法（NJ）和最大简约法（MP），对14株念珠藻的16S rRNA基因序列进行系统发育分析，两种方法得到的系统发育树基本一致。结果显示：（1）三者间的遗传距离（0.0129-0.0261，平均值0.0203）均大于普通念珠藻的种内遗传距离（0.0007-0.0118，平均值0.0074），超过了种内差异程度，在系统树中这3种念珠藻分别聚簇在不同的分支上；（2）地木耳、发菜和葛仙米与裂褶念珠藻等其它7种念珠藻间的遗传距离（0.0423-0.0996，平均值0.0561）大于三者间的遗传距离，在系统树中聚类较近，而与其它念珠藻聚类较远。据此，可将地木耳、发菜和葛仙米归为念珠藻属3个不同的种，并且它们的亲缘关系较近。
The 16S rRNA gene sequences of Nostoc commune, N. flagelliforme and N. sphaeroides were obtained by 16S rRNA gene cloning and sequencing. The phylogenetic analysis among 14 strains and a out-group （Synechocystis sp. ） were constructed based on 16S rRNA gene sequences by neighbor-joining （NJ） method and maximum parsimony （MP） method. The NJ tree was basically consistent with the MP tree. The results showed： （1）The genetic distances among N. commune, N. flagelliforme and N. sphaeroides （0. 012 9-0. 026 1, average 0. 020 3） were more than the intraspecific genetic distances of N. commune （0. 000 7-0. 011 8,average 0. 007 4）, beyond the extent of the intraspecific differences. The three species were clustered in different clades respectively; （2） The genetic distances among the three species and other seven species of Nostoc including N. cf. verrucosum （0. 042 3-0. 099 6,average 0.056 1） were longer than those among the three species. In the phylogenetic trees N. commune, N. flagelliforme and N. sphaeroides were clustered closer, but they had further relations with other species of Nostoc. So, N. commune, N. flagelliforme and N. sphaeroides should belong to three different species of the genus Nostoc, but the relationships among them are close.
出处
《西北植物学报》
CAS
CSCD
北大核心
2008年第3期459-464,共6页
Acta Botanica Boreali-Occidentalia Sinica
