乌头霜霉病病原菌rDNA-ITS和28S rDNA D1/D2区序列分析

rDNA-ITS and 28 S rDNA D1/D2 sequence analysis of downy mildew pathogen from Aconitum carmichaeli

目的明确四川江油地区栽培乌头霜霉病病原菌乌头霜霉Peronospora aconiti rDNA-ITS和28 S rDNA D1/D2区序列,为病害诊断和防治提供理论基础。方法从病株收集病原菌分生孢子及菌丝,提取DNA,扩增rDNA-ITS和28 S rDNA D1/D2片段序列,进行测序分析,并构建邻接(neighbor-joining,NJ)发育树分析病原菌种类。结果检测出的病原菌rDNA-ITS序列与NCBI数据库中霜霉属P.pulveracea、P.aparines相似度为94%,28 S rDNA D1/D2区序列与霜霉属P.pulveracea、P.ficariae、P.bulbocapni相似度达97%。结论分子rDNA-ITS和28 S rDNA D1/D2区序列鉴定的结论和形态学鉴定的结论一致,乌头霜霉病病原菌为霜霉科霜霉属乌头霜霉Peronospora aconiti Yu,其rDNA-ITS和28 S rDNA D1/D2区序列可用于该病原物的鉴定。

Objective To define sequences about rDNA-ITS and 28 S rDNA D1/D2 ofPeronospora aconiti separated from cultivated Aconitum carmichaeli in Jiangyou area of Sichuan province and provide a theoretical basis for the diagnosis and prevention of downy mildew disease. Methods Spores and hyphae ofP. aconiti from diseased plants were collected and total genomic DNA of pathogen were extracted and then rDNA-ITS and 28 S rDNA D 1/D2 fragment were amplified and sequenced. According to the above results, the abutment （Neighbor-joining, NJ） phylogenetic tree of pathogen was constructed and analyzed. Results The rDNA-ITS and 28 S rDNA DI/D2 sequences of P. aconiti were sequenced and compared according to the database from NCBI. Compared that with P. pulveracea and P. aparines, the similarity of rDNA-ITS sequences of P. aconiti was 94%. The similarity of 28 S rDNA D1/D2 sequences of P. aconiti was 97% compared that with P. pulveracea, P. ficariae and P. bulbocapni. Conclusion The results of morphological identification of downy mildew pathogen separated from A. carmichaeli are consistent with those from molecular identification （rDNA-ITS and 28 S rDNA D1/D2 sequences） and the pathogen of Aconitum downy mildew should be P aconiti. Therefore, rDNA-ITS and 28 S rDNA D 1/D2 sequences constructed in this paper can be used to identify downy mildew pathogen from Aconitum carmichaeli Debx.