软腐白菜细菌群落结构多样性与生长环境的相关性

Correlation of bacterial diversity in rot Chinese cabbage with the habitat

摘要:

摘要:【目的】通过对比分析不同生境白菜软腐病变组织与根系土壤相关细菌的群落结构，探讨白菜软腐细菌种群的多样性，以及与生境土壤细菌种群的相关性。【方法】样品采自河南省2 个不同生态型白菜田，以成熟白菜软腐组织及病株根系土壤为目标，利用模拟原环境的培养基成分和条件，对样品中的细菌进行高通量分离培养和细胞16S rRNA 基因序列比对分析，获得各样品细菌种群结构及其丰度，进而对各样品的优势菌群进行对比分析。【结果】两种不同生境白菜软腐组织细菌总量M05T为4.0×108cell/g、Q2T 为1.2×1011 cell/g，分别获得纯菌56 株和85 株。M05T 优势菌为萎蔫短小杆菌萎蔫亚种(Curtobacterium flaccumfaciens pv．Flaccumfaciens);Q2T 优势菌为假单胞菌( Pseudomonas spp．) (栖木槿假单胞菌(P．hibiscicola)、台湾假单胞菌(P．taiwanensis)、托木尔假单胞菌(P．tuomuerensis)、莫塞尔假单胞菌(P．mosselii))。根系土壤细菌总量M05S 为2.7×105 cell/g、Q2S为6.2×107 cell/g，分别获得纯菌36株和70株。M05S 优势菌为巨大芽胞杆菌(Bacillus megatherium);Q2S 优势菌为假单胞菌( Pseudomonas spp．) (香鱼假单胞菌(P．plecoglossicida)、栖木槿假单胞菌(P．hibiscicola)、类黄色假单胞菌(P．parafulva)、蒙氏假单胞菌(P．monteilii)、膝形假单胞菌(P．geniculata))。【结论】依据不同生境的白菜软腐组织和根系土壤细菌群落结构对比分析，认为白菜软腐菌可能具有多样性和多种致病来源，本研究为软腐病多种防治措施的制定提供基础研究和菌种资源。

Abstract:

Abstract:［Objective］ To investigate the diversity of bacteria in soft rot Chinese cabbage and analyze their correlation with rhizosphere bacteria，we analyzed the bacterial population structures of soft rot Chinese cabbage and the rhizosphere in different habitat．［Methods］ Based on the initial medium and artificial Chinese cabbage medium，we isolated the bacteria from soft rot tissues and rhizospheric soils from two typical habitats． According to the analysis of 16S rRNA gene sequence homology，we identified the isolated strains and analyzed the strains population structure．［Results］ The total bacteria in soft rot tissues were 4.0×108 cell g－1 and 1.2×1011 cell g－1，the number of pure strains were 56 and 85，the dominant strains were Curtobacterium flaccumfaciens pv．flaccumfaciens and Pseudomonas spp．(P．hibiscicola，P.taiwanensis，P.tuomuerensis，P.mosselii)．The total bacteria in rhizospheric soils were 2.7×105 cell g－1 and 6.2×107 cell g－1，the number of pure strains were 36 and 70，the dominant strains were Bacillus megatherium and Pseudomonas spp．(P．plecoglossicida，P．hibiscicola，P．parafulva，P．monteilii，P．geniculata)．［Conclusion］ The methods used in this study were effective in analyzing bacterial diversity in soft rot Chinese cabbage and the results correlated well with the soil bacteria analysis，suggesting that soft rot Chinese cabbage may be induced by various environmental bacteria． Our results infer that soft rot of Chinese cabbage might be pathogen-complex，and provide the clues for the mechanism study and protection．