[目的]明确生防菌EN5菌株在番茄根、茎及根际土壤中和在黄瓜、烟草体内的定殖情况,及对根际土壤微生态的影响,为细菌性青枯病的生态治理提供理论依据.[方法]采用抗杭生素抗性标记法测定生防芽胞杆菌EN5的定殖能力;以平板培养及ERIGPCR法分析菌株EN5对番茄根际土壤微生物种群的影响.[结果]菌株EN5在番茄根、茎及根际土壤中均能稳定定殖,当菌株EN5处理植株15d时,其在番茄茎内的定殖量可达5.6×10(4)cfu/g;此外,菌株EN5在烟草和黄瓜体内亦可定殖,其在烟草体内的定殖量较大.菌株EN5处理使根际土壤中细菌、真菌和放线菌的数童明显高于对照土壤,对氨化细菌、固氮菌、纤维素降解菌等微生物群体有促进作用,对反硫化细菌群体有抑制作用.同时,菌株EN5处理还改善了根际土壤中细菌群体的多样性.[结论]菌株EN5可以在其自然寄主番茄的根、茎及根际土壤中稳定定殖.同时,菌株EN5处理有助于改善根际土壤微生态环境,抑制病菌繁殖.%[Objective]The colonization capacity of biocontrol Bacillus strain EN5 in tomato, cucumber and tobacco plants was investigated, and the effects of EN5 on tomato rhizesphere soil microbial communities were also studied, which will provide a basis for ecological control of the disease.[Method]The colonization trends of biocontrol Bacillus strain EN5 in plants was examined with the method of antibiotic-resistance.Furthermore, the effect of EN5 on tomato rhizosphere soil microbial communities was investigated using plate culture method and ERIC-PCR.[Result]It showed that EN5 colonized the stem, root and rhizosphere soil stably; and the population of EN5 in stem was 5.6× l04 cfu/g 15 days after inoculation.It was also found that EN5 could colonize tobacco and cucumber, and the population of EN5 in tobacco was obviously larger than that in cucumber.EN5 treatment raised the amounts of bacteria, fungi and actinomycetes significantly, and promoted the growth of ammonifier,nitrite bacteria and cellulose-decomposer, but inhibited that of desulphate bacteria.In addition, the diversities of bacteria in rhizosphere soils were improved by EN5 treatment as well.[Conclusion]EN5 could colonize the tomato stem, root and rhizosphere soil stably, and facilitate the improvement of the rhizosphere soil micro-ecological environment, but suppressed the pathogen propagation.
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