中国马铃薯疮痂病病原菌16S rDNA的遗传多样性分析

 【目的】利用16S rDNA序列对来自中国8个省（区）的34株马铃薯疮痂病菌和15株参比菌株进行系统发育分析。【方法】采用链霉菌通用引物对34株测试菌株的基因组进行16S rDNA序列扩增，测序后在GenBank中进行BLASTn比对，选取同源性较高的菌株构建系统发育树。【结果】34个测试菌株均为链霉菌属，其中Streptomyces scabies 12株、S. galilaeus 8株、S. bobili 6株、S. turgidiscabies 1株、S. acidiscabies 1株、S. diastatochromogenes 2株、S. setonii 1株、S. enissocaesilis 3株。其中S. galilaeus、S. bobili和S. enissocaesilis等种均为新发现的疮痂病病原。对各菌株的分布分析发现，山东省的疮痂病菌有4种，内蒙古自治区和陕西省有3种，四川省、河北省和山西省均有2种，黑龙江省为1种。【结论】中国马铃薯疮痂病菌存在明显的遗传多样性，且分布较为复杂。

Genetic Diversity of Potato Scab Pathogens in China Based on 16S rDNA Sequences

【Objective】 Phylogenetic tree was constructed from 15 standard potato scab pathogen strains and 34 scab-causing strains isolated from 8 provinces in China based on the 16S rDNA gene sequences. 【Method】 16S rDNA sequences were obtained using Streptomyces genus universal primers and genomic DNA as amplified template by PCR technique. BLASTn algorithm was used to search alignment for the sequences of 16S rDNA gene from the 49 strains against GenBank nucleotide database. Among them, strains with higher sequence homology were used to construct a phylogenetic tree by Clustal X 1.8 and MEGA 2.1 softwares. 【Result】 Based on the results of phylogenetic analysis, the 34 scab-causing strains tested in this paper were attributed to the Streptomyces genus. Among them, 12 strains belong to S. scabies, 8 to S. galilaeus, 6 to S. bobili, 2 to S. diastatochromogenes, 1 to S. turgidiscabies, 1 to S. acidiscabies, 1 to S. setonii, and 3 to S. enissocaesilis. Moreover, S. galilaeus, S. bobili and S. enissocaesilis are identified as novel potato scab pathogens for the first report. Four strains were isolated from Shandong province, 3 from Inner Mongolia province and 3 from Shaanxi province, 2 from Hebei province, 2 from Shanxi province, 1 from Heilongjiang province. 【Conclusion】 Results suggested that genetic diversity and complex regional distribution existed for potato scab pathogens in China.