扁茎变异茅苍术植原体的分子检测及鉴定

Molecular Detection and Identification of'Candidatus Phytoplasma asteris'Related Strain Associated with Atractylodes lancea

茅苍术种植基地内发现少数植株表现为扁茎、叶序紊乱、花变叶等症状,与植原体侵染引发的症状类似。为确定是否是植原体侵染,以及是何种植原体侵染,本研究利用植原体通用引物P1/P7和R16F2n/R16R2对扁茎变异茅苍术植原体的16S rDNA基因序列进行巢式PCR扩增、克隆、测序,并进行分析。结果表明,所得扩增产物约1.2 kb的植原体特异片段,通过对实验结果分析,确定该苍术变异原因为植原体感染。系统进化分析结果表明,引起茅苍术发生扁茎变异的植原体属于翠菊黄化组(Aster yellows group)16SrI-B亚组。本研究首次从分子水平确定了引起中国湖北英山地区茅苍术扁茎变异的病原菌为植原体,明确了其分类地位,为指导苍术该病害流行学研究和苍术植原体防治提供了理论依据。

The symptoms of stem fasciation and proliferation,phyllotaxy disorder,floral virescence,inflorescence abnormality were noticed in plants of Atractylodes lancea in Yinshan,Hubei Province,which were suggestive of phytoplasma infection.Molecular diagnostics was then employed with the universal primers P1/P7 and R16F2n/R16R2 to conduct nested PCR amplification,resulting in DNA amplicons that were 1.2 kb in symptomatic samples tested.No amplicons were generated from symptomless samples,which suggested association of a phytoplasma infection.The phylogenetic tree based on phytoplasma 16S rDNA sequence showed that the phytoplasma clustered with members of Aster yellows group(16SrI-B).The identified phytoplasma strain could be a potential problem for the production of rhizomes of A.lancea.Thus,this results paved the way for the epidemiology study and prevention of the disease.