吡咯伯克霍尔德氏菌JK-SH007对杨树根际微生物数量及功能多样性的影响

摘要

【目的】为揭示生防菌吡咯伯克霍尔德氏菌JK-SH007进入自然环境后对周围的微生态因子是否存在威胁，对其进入自然环境后的微生态效应和生物安全性做出正确评估。【方法】采用固体平板法研究 JK-SH007菌株对美洲黑杨盆栽苗土壤微生物种群数量的影响，对4种主要土壤酶(酸性磷酸酶、碱性磷酸酶、脱氢酶、转化酶)的活力进行测定，并通过 Biolog ECO 微孔板法分析 JK-SH007菌株对美洲黑杨土壤功能多样性的影响。【结果】从整体趋势来看，在美洲黑杨根际引入 JK-SH007菌株后，随着时间延长，根际土壤中的细菌、放线菌、真菌数量逐渐高于对照，且差异显著，在接种后150天接种处理达到峰值(3.36×109cfu·g －1干土；7.50×107cfu·g －1干土；1.14×107 cfu·g －1干土)，随后显著降低，但仍优于未接种处理； JK-SH007处理后土壤酶活性均有所增强，土壤酸性磷酸酶、碱性磷酸酶、脱氢酶、转化酶活性均大于对照，其中，接种对碱性磷酸酶、转化酶活性的促进最为明显；根际土壤中微生物的 AWCD 值(除了在接种后30，90天时)，接种处理和未接种处理的 AWCD值相当，几乎持平；而接种后10，20，60，120，150，180天时接种处理土样微生物的 AWCD 值均高于 CK；土壤微生物多样性( Shannon 指数、Simpson指数和 McIntosh指数)在接种前期没有明显的规律性，与对照几乎持平，120，150，180天时，接种 JK-SH007处理的 Simpson指数、Shannon指数、McIntosh指数均高于对照，但差异不显著。【结论】在根际引入 JK-SH007对美洲黑杨根际土壤微生物的整体活性和功能多样性的提高有一定的促进作用，在一定程度上丰富了土壤微生物种群，有利于保持和促进土壤肥力和健康状况，但这些影响随着时间的延长而减弱；同时也说明 JK-SH007菌株的施入不会对环境中土著微生物构成威胁或威胁较小，符合 Bcc菌的安全应用范围，进一步证明该菌株的生物安全性，为将来该菌株的野外应用及生防菌剂的开发奠定基础。%[Objective]Burkholderia pyrrocinia JK-SH007 is a strain of biocontrol bacteria which was isolated from the stem of poplar. In order to evaluate the safety of B. pyrrocinia JK-SH007,this study aimed to evaluate the micro ecological effects and the biological safety of the natural environment after its entry into the natural environment.[Method]A solid plate method was used to investigate the potential effects of JK-SH007 on the activity change of the four main soil enzymes,and the Biolog ECO microplate method was applied to assay the microbial community and its function diversity in rhizosphere soil of aigeiros poplar ( Populus deltoides) .[Result]The results showed that from the over trend, the numbers of bacteria,actinomyces and fungi in poplar rhizosphere soil gradually increased and were significantly higher than control with the extension of time after being inoculated with strain JK-SH007 . The number of these microorganisms reached the peak (3. 36 × 109 cfu·g -1 dry soil; 7. 50 × 107 cfu·g -1 dry soil; 1. 14 × 107 cfu·g -1 dry soil) in 150 day post-inoculation,and then decreased significantly,but by then were still higher than these of control plants. The soil enzymes activities (acid phosphatase,alkaline phosphatase,dehydrogease and invertase) with inoculation of strain JK-SH007 were all higher than that of control,especially for alkaline phosphatase and invertase. The Biolog ECO plates analysis showed that AWCD values on day 10,day 20,day 60,day 150 and day 180 after inoculation were higher than control treatment. At the early stage of the inoculation,soil microbial diversity ( Shannon index,Simpson index and McIntosh index) had no obvious regularity. At the 120th day,150th day and 180th day post-inoculation,the three parameters of the functional diversity of the soil microbial communities were all slightly higher than those of control. But, the differences were not significant. [Conclusion]Strain JK-SH007 may play roles in improving total microbial activity of poplar rhizosphere soil,increasing soil fertility and enriching soil communities. All of these are conductive to maintaining and promoting the soil fertility and health. But these benefits would be decline over time. At the same time,all of results showed strain JK-SH007 had no or less menace to the indigenous microorganisms in the environment,suggesting that it is safe to put strain JK-SH007 into use as a potential bio-control factor in the future.