从我国20种感病植物中扩增植原体16S rDNA片段及其RFLP分析

本研究收集了２０种感染植原体的植物材料，从患病材料和相应健康植物组织中提取总ＤＮＡ用作ＰＣＲ模板，选择两对通用引物进行巢式ＰＣＲ，扩增植原体的１６ＳｒＤＮＡ片段，回收扩增产物，通过限制性酶切片段长度多态性（ＲＦＬＰ）分析进行分类。２０种患病植物材料中的植原体有１３种属于翠菊化种，２种属于白对黄化种，３种属于花生丛枝种，２种属于三叶草丛生种。

AMPLIFICATION OF PHYTOPLASMA 16S rDNA FROM 20 INFECTED PLANTS IN CHINA AND THEIR RFLP ANALYSIS

We extracted DNA from 20 infected plants and their healthy counterparts collected in China, amplified the phytoplasma 16S rDNA fragments by nested PCR. The primer pair R16F2/R16R2 amplified a 16S rDNA fragment (about 1.2kb) from each DNA sample prepared from 20 infected tissues but not from any DNA sample extracted from healthy tissues. We purified the nested PCR products and connected it into T vector for storage. The 16S rDNA fragments amplified were compared through RFLP analysis. Based on the similarity of RFLP patterns, these 20 phytoplasmas could be classified into 4 distinct 16S ribosomal RNA groups, corresponding to: Aster yellows (Paulownia witches' broom, Hackberry witches' broom, Periwinkle witches' broom, Fernleaf hedge bamboo witches' broom, Hibiscus fasciated disease, Chinaberry tree witches' broom, Chinese thorny bamboo witches' broom, Tobacco witches' broom, Banana bunchy top, Evergreen chinkapin witches' broom, Willow yellows, Mulberry yellow dwarf disease, Mulberry dwarf disease); Ash yellows(Cherry fasciated disease, Jujube witches' broom); Peanut witches' broom ( Stylosanthes gracilis H.B.K .witches' broom, Groundnut witches' broom, Stylosanthes guianensis cv. Witches' broom ) and clover proliferation (Bishopwood witches' broom, Cinnamon yellows).