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作 者 ：刘艳霞 李想 曹毅 陆宁 石俊雄

期 刊 ：植物营养与肥料学报 2014年 20卷 5期 页码：1203-1211

关键词：烟草青枯病；生物有机肥；田间试验；土壤微生物群落结构多样性；微生物群落功能多样性；

Keywords:tobacco bacterial wilt, bio-organic fertilizer, field experiment, structural diversity of soil microbial community, functional diversity of soil microbial community,

摘 要 ：【目的】烟草青枯病是影响烟叶生产最主要的土传病害之一，生物防控烟草青枯病是近年来的研究热点。为验证抑制烟草青枯病型生物有机肥对生防青枯病的影响，进行2年田间试验研究其防效及其对土壤微生物的影响。【方法】本试验采用从烟草根际原位土壤分离得到的烟草青枯病拮抗菌株L-25和L-9，利用有机肥二次固体发酵技术，制成烟草青枯病拮抗生物有机肥。连续两年在安徽进行田间试验，分别在烟草移栽后50天和105天调查生物防控率，探求生物有机肥对青枯病的田间防效和对烟叶产量的影响；利用平板计数法、Biolog特征性碳源法和梯度变性凝胶电泳法摸索生物有机肥施用后根际土壤微生物数量、群落功能多样性和结构多样性的变化，揭示生物有机肥对青枯病的防控机理。【结果】 1）第一年和第二年施用生物有机肥处理移栽50天后烟草青枯病的生物防控率分别为82.2%和96.2%，105天后烟草青枯病的生物防控率分别达到75.2%和95.4%； 2）生物有机肥处理第一年和第二年烟叶产量分别为2212.5 kg/hm²、1475.5 kg/hm²，是对照的2.4和2.6倍； 3）两年生物有机肥处理的根际土壤可培养细菌、放线菌数量均显著高于对照，真菌数量显著低于对照（P＜0.05），其中第一年生物有机肥处理50天和105天拮抗菌数量分别为对照的241.8倍和13.4倍，病原菌数量仅为对照的19.7%和56.6%，第二年生物有机肥处理50天和105天拮抗菌数量分别是对照的111.0倍和26.7倍，病原菌数量仅为对照的9.1%和31.4%； 4）两年生物有机肥处理50天和105天根际土壤的微生物群落功能多样性，即Shannon指数、Simpson指数和Mclntosh指数均显著高于对照（P＜0.05）； 5）生物有机肥处理与对照土壤微生物群落结构也不相同，细菌和真菌梯度变性凝胶电泳图谱明显不同，分别属于不同的聚簇，生物有机肥处理的细菌种类较对照有所增加，同时真菌的种类有所减少。【结论】在烟草青枯病发病较为严重的烟田施用生物有机肥，可以显著降低青枯病发病率，增加烟草产量。生物有机肥可以显著提高拮抗菌数量，抑制根际土壤病原菌的数量，提高土壤微生物群落功能多样性，改善微生物种群和组成，丰富土壤微生物群落结构，使土壤保持健康的微生物生态平衡。

Abstract:【Objectives】Tobacco bacterial wilt is one of the most serious soil-borne diseases for tobacco production. The biocontrol of tobacco bacterial wilt has become a hot topic recently. To investigate effect of specific bio-organic fertilizers on biocontrol of tobacco bacterial wilt, a two-year field experiment was conducted to investigate the biocontrol efficiency and soil microbial community.【Methods】 In this experiment, two antagonistic strains (L-25 and L-9) with strong inhibitory effects on Ralstonia solanacearum in vitro were isolated from rhizosphere soil in a severely wilt-diseased field. Two solid bio-organic fertilizers (BOF) were secondly fermented by the two antagonists, strain L-25 and L-9. A two-year field experiment was conducted in Anhui Province. The biocontrol efficiency was investigated at 50 d and 105 d after tobacco transplanting. The effects of the bioorganic fertilizers on soil microbial community and tobacco yield were measured and analyzed. In order to reveal the biocontrol mechanism of the bioorganic fertilizers, the colony counting method, biolog phenotype analysis and denaturing gradient gel electrophoresis (DGGE) were used to analyze microbial population, functional and structural diversity of microorganisms, respectively in rhizosphere soil after the application of the bioorganic fertilizers.【Results】1）At 50 d after the transplanting, compared with the control, the control efficiencies of the BOF treatments reach to 82.2% and 96.2% for the first and second year, respectively, and to 75.2% for the first year and 95.4% for the second year at 105 d after the transplanting. 2）The tobacco yields are increased to 2212.5 kg/ha and 1475.5 kg/ha in the first and second year in the BOF treatments which are about 2.4 times and 2.6 times of control, respectively. 3） The populations of rhizosphere cultivated bacteria and actinomycetes of the BOF treatments are significantly higher than those of the control, while the counts of fungi of the BOF treatments are significantly lower than those of the control (P＜0.05). In the first year, the populations of antagonists are increased by 241.8 times and 13.4 times of the control in 50 d and 105 d after the transplanting in the BOF treatments, while the populations of pathogen are 19.7% and 56.6% of the control, respectively. In the second year, the counts of antagonists are increased by 111.0 times and 26.7 times of the control in 50 d and 105 d after the transplanting in the BOF treatments. However, the pathogen counts in the BOF treatments are 9.1% and 31.4% of the control. 4）The Shannon Index, Simpson Index and Mclntosh Index of soil microbial community of the BOF treatments are significantly higher than those of the control in both 50 d and 105 d after the transplanting in the two years. 5）There are significant differences of soil microbial structural diversity between the BOF treatments and the control. The denaturing gradient gel electrophoresis (DGGE) patterns of soil bacteria and fungi of the BOF treatments and the control treatment belong to two corresponding clusters，which suggests that bacterial species are increased and fungi species are decreased under the application of BOF. 【Conclusions】The application of tobacco specific BOF in the severely wiltdiseased tobacco field can significantly reduce the wilt disease incidence and thus increase tobacco yield. Bioorganic fertilizer depresses the population of the pathogen and increases the counts of antagonists. Meanwhile, it can increase the functional diversity of the soil microbial community and improve the microbial structural diversity. Therefore, the soil micro-ecology keeps balanced.

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