无致病力青枯雷尔氏菌对烟草根系土壤微生物脂肪酸生态学特性的影响

为了探讨无致病力青枯雷尔氏菌对烟草根系土壤微生物群落结构的影响,测定了接种无致病力青枯雷尔氏菌RS-1403和清水对照的烟草根系土壤的磷脂脂肪酸(Phospholipid Fatty Acids,PLFAs),比较分析两种处理下的烟草根系土壤微生物PLFAs组成、含量、微生物群落结构及多样性的差异,以期从微生物群落水平解析RS-1403菌株胁迫对烟草青枯病的免疫抗病机制。结果表明,与对照相比,RS-1403菌株胁迫下烟草根系土壤微生物PLFAs的组成及含量发生了变化,分为5种变化类型,分别为下降型、无变化型、增加50%以下类型、增加50%—100%类型,增加100%以上类型,其中指示放线菌的10Me16∶0含量降低,为下降型,增加100%以上类型的PLFAs均指示革兰氏阴性菌。进一步分析表明,接种RS-1403菌株能改变烟草根系土壤微生物群落结构,促进细菌和真菌的生长,抑制放线菌的生长。接种RS-1403菌株能提高烟草根系土壤的群落优势度Simpson指数、群落丰富度Shannon指数和均匀度Pielou指数,增加土壤的微生物群落多样性。对RS-1403菌株胁迫下烟草根系土壤微生物亚群落分化的比较分析,显示RS-1403菌株处理组与对照组亚群落分化不同,当兰氏距离为2.56时,可将处理组和对照组均分为4个亚群落,但它们的各亚群落组成及特征不同。聚类分析表明,基本上可将取样期内的RS-1403菌株胁迫处理和清水对照的烟草根系土壤分别聚在两个不同的类群中,说明RS-1403菌株能明显改变烟草根系土壤微生物群落结构。

Effect of the avirulent strain of Ralstonia solanacearum on the ecological characteristics of microorganism fatty acids in the rhizosphere of tobacco

In order to study the effects of avirulent Ralstonia solanacearum on soil microbial community structures in the root system, the phospholipid fatty acids (PLFAs) from the samples of tobacco in the different date were detected.. The pattern, content and structure of PLFAs in the treatment with plant vaccin of avirulent strain R. solanacearum and in the treatment with water control were compared.The results showed that plant vaccin of avirulent strain R. solanacearum stress changed PLFAs pattern and content of tomato root soil, which could divided five groups that declined type, unchanged type, increased 50% type, increased 50-100% type, and inceaded more than 100% type. Moreover, plant vaccin of avirulent strain R. solanacearum treatment changed the diversity of microbial comunities in the tobacco rhizosphere, that promoted the growth of bacteria and fungi, inhibited the growth of actinomycetes. We also found that plant vaccin of avirulent strain R. solanacearum could increased the community diversity of tobacco rhizosphere when based on the indexes of Shannon, Simpson and pielou, Compared the subcommunity differentiation between the tobacco rhizosphere soil of avirulent Ralstonia Solanacearum treatment and contrast, we found that subcommunity of treatment group and contrast group could all divided into four groups with Lance distance 2.56, however, the compose and characterize of them were different. The cluster analysis analysis showed that the root soil of tobacco under plant vaccin of avirulent strain R. solanacearum treatment and contrast treatment were belonged to two different groups, which indicated that plant vaccin of avirulent strain R. solanacearum treatment could change the soil microbial community.