小麦蓝矮病植原体16S rDNA序列分析研究

Sequence analysis of 16S ribosomal DNA of phytoplasma associated with wheat blue dwarf

小麦蓝矮病是我国西北地区冬小麦上一种重要病害。本研究利用植原体16S rDNA通用引物对小麦蓝矮病患病植株全DNA进行nest-PCR扩增,获得1.2 kb的特异片段,并对扩增产物进行核苷酸序列测定,从分子水平证明了小麦蓝矮病的病原是植原体。利用最大简约法构建了16S rDNA系统演化树,系统演化关系分析表明:小麦蓝矮病植原体应该归属于翠菊植原体(CandidatusPhytop lasm a asteris);小麦蓝矮病植原体与三叶草变叶病植原体(CPh)关系密切,被聚类为同一亚组(16Sr I-C),但是它们在寄主范围和传播介体等生物学性状方面差异很大。

Wheat blue dwarf is an important disease on winter wheat in northwestern China. A 1.2 kb fragment was amplified by nested-PCR phytoplasma universal primers and total DNA sample extracted from diseased wheat as the amplified template. Nucleofide sequencing of the amplified fragment indicated that wheat blue dwarf disease was caused by a pathogenic phytoplasma. A phylogenefic tree based on 16S ribosomal DNA sequences was constructed and showed that wheat blue dwarf phytoplasma was clustered into the Candidatus Phytoplasma asteris, subgroup 16Sr I-C. Wheat blue dwarf phytoplasma and clover phyUody phytoplasma had a high similarity on 16S rDNA sequences, but differed in host range and dissemination agent.