9种热区植物白粉病菌的rDNA-ITS序列及系统发育分析

为弄清橡胶树、野艾蒿、大尾摇、胡萝卜、车前草、马占相思、红木、苦瓜和九里香等热区植物上白粉病菌的种类和彼此之间的系统发育关系,对这些白粉病菌的rDNA-ITS序列进行扩增和测序,与GenBank上公布的序列进行同源性比对,并进行分类.结果表明:橡胶树、马占相思、红木和九里香上的白粉病菌相似性非常高,均在99％以上；野艾蒿、大尾摇和苦瓜白粉病菌与叉丝单囊壳白粉菌的亲缘关系较近,分别达到100％和99％;胡萝卜白粉病菌与白粉菌属的独活白粉菌相似性在99％以上；而车前草白粉病菌与污色白粉菌的相似性达100％.利用供试菌和GenBank上公布的rDNA-ITS序列构建了系统发育树,将供试白粉菌分为4个类群,确定供试白粉菌之间的亲缘关系.

Phylogenetic Relationships and rDNA- ITS Sequence Analyses of Powdery Mildews on Some Plants in Tropical Regions

To understand the species and the phylogenetic relationships of powdery mildew fungi from Hevea brasiliensis, Artemisia princes, Momordica charantia, Daucus carrot, Plantago asiatica, Acacia auriculaeformis, Murraya exotica, Bixa orellana, Heliotropium indicum, the ribosomal DNA internal transcribed spacer(ITS)region of the genomic DNAs were amplified and subsequently sequenced. BLAST and the homologous analysis of ITS sequences were conducted in the GenBank database. The result indicated that the powdery mildew fungi had over 99% ITS sequences homology from Hevea brasiliensis, Bixa orellana, Murraya exotica and Acacia auriculaeformis. The powdery mildew fungi, isolated from Artemisia princes, Heliotropium indicum and Momordica charantia, and Podosphaera genus were closely related, The ITS sequences homology was 99% between the powdery mildew fungi of Daucus carrot and Erysiphe heraclei. The ITS sequences homology reached to 100% between the powdery mildew fungi of Plantago asiatica and Golovinomyces sordidus. The phylogenetic trees were constructed using the nucleotide sequences of the rDNA ITS region from a total of 49 ITS sequences examined, which were divided into four groups.