南京及周边地区螺原体菌株的系统发育及遗传多样性分析

利用系统发育分析和RAPD技术对我国南京及周边地区的20株昆虫和植物花螺原体的分类地位和遗传多样性进行分析。结果表明:大多数菌株与Spiroplasma melliferum聚类,位于以16S rDNA序列构建的螺原体系统发育树的Citri-Chry-sopicola-Mirum类群;菌株ZHUF0901和MF0905位于Apis群内,但二者又分为2个不同的分支。利用筛选的34条RAPD引物共检测出664个位点,其中多态性位点数644个,多态性比率为96.99%。UPGMA聚类分析表明,在相似性系数达到0.6时,与Spiroplasma melliferum聚类的18株菌可根据螺原体宿主的不同分为明显的3个类群,菌株ZHUF0901与MF0905各为一类。同一时期不同宿主(植物花、蜜蜂以及其他昆虫)中的蜜蜂螺原体Spiroplasma melliferum亲缘关系很近,说明自然界中螺原体可通过水平传播方式进行传播。

Phylogenetic analysis and genetic diversity of spiroplasma isolates from Nanjing and its surrounding areas

Polygenetic relationship and genetic diversity of 20 spiroplasma isolates,which were isolated from insects and flowers in Nanjing and its surrounding areas,were analyzed by phylogenetic analysis and random amplified polymorphic DNA(RAPD)markers.The results showed that most isolates had a close relationship with Spiroplasma melliferum,and were located in the Citri-Chrysopicola-Mirum clade of the phylogenetic tree generated by using the 16S rDNA sequence.Both isolate ZHUF0901 and MF0905 belonged to the Apis clade but were divided into two different sub branches.34 RAPD random primers produced a total of 664 alleles,of which 644 were polymorphic with a polymorphism percentage of 96.99%.The UPGMA dendrogram suggested that all spiroplasma isolates were divided into 5 groups when similarity coefficient was 0.6.Eighteen spiroplasma isolates clustered with Spiroplasma melliferum were divided into 3 groups according to their different hosts.ZHUF0901 and MF0905 each formed an independent group.The spiroplasmas isolated from different hosts(plant flowers,bee and other insects)during the same period had a close relationship with each other,indicating that spiroplasmas were transmitted by horizontal transmission in nature.