生物有机肥对连作蕉园香蕉生产和土壤可培养微生物区系的影响

Effects of continuous application of bio-organic fertilizer on banana production and cultural microflora of bulk soil in orchard with serious disease incidence

以连续种植香蕉12年的枯萎病高发病蕉园为试验点,通过平板计数和可培养微生物群落变性凝胶电泳(CD PCR-DGGE)等方法研究田间条件下连续两年施用化肥、牛粪、猪粪和生物有机肥对香蕉枯萎病的抑制作用,以及对香蕉产量、品质和土壤中可培养微生物区系的影响.结果表明:相比于其他处理,连续两年施用生物有机肥能够有效降低香蕉枯萎病发病率,显著提高大田香蕉单株质量、小区产量、果实可溶性糖含量及可溶性糖与可滴定酸的比值(糖酸比).可培养微生物区系分析结果表明,施用生物有机肥能够显著提高土壤微生物生物量,增加可培养细菌、芽孢杆菌和放线菌数量及细菌与真菌比值,降低尖孢镰刀菌数量.CD PCR-DGGE聚类分析表明,连续两年施用生物有机肥明显改变了土壤可培养细菌群落结构,增加了其丰度和多样性.切胶测序结果表明,连续两年施用生物有机肥的香蕉园土壤增加了类芽孢杆菌、伯克氏菌、未培养疣微菌及Bacillus aryabhattai的丰度,降低了青枯菌、粘金黄杆菌、Fluviicola taffensis、肠杆菌及巨大芽孢杆菌的丰度.表明连续施用生物有机肥能够优化连作蕉园土壤可培养微生物群落结构,防控香蕉枯萎病的发生,提高香蕉产量并改善果实品质.

A field experiment was conducted for two years to investigate the effects of different ferti- lization applications on the suppression of banana fusarium wilt disease, crop yield, fruit quality and cuhurable microflora in a banana orchard which has been monocultured with banana for 12 years and suffered serious banana fusarium wilt disease. The fertilizers included chemical fertilizer （CF） , cow manure compost （CM） , pig manure compost （PM） and bio-organic fertilizer （BIO）. The ba- nana soil microflora was invested using plate-counting method and culture-dependent polymerase chain reaction denaturing gradient gel electrophoresis method （CD PCR-DGGE ）. Results showed that, compared with the other treatments, 2-year consecutive application of BIO significantly re- duced the banana fusarium wilt disease incidence, and improved the banana mass per tree, crop yield, total soluble sugar content and the ratio of total soluble sugar to titratable acidity of fruits （ sugar/acid ratio）. Moreover, the analysis of culturable microflora showed that BIO application sig- nificantly increased the soil microbial biomass, soil cuhurable bacteria, bacillus and actinomycetes, and the ratio of bacteria to fungi （B/F） , while decreased the Fusarium oxysporum. Based on the CD PCR-DGGE results, the BIO application significantly altered the soil culturable bacterial struc- ture and showed highest richness and diversity after 2 years of BIO application. The Dhvlo^enetic analysis of the selected bands showed that BIO application enriched the soil with the species of Paenibacillus sp., Burkholderia sp., uncultured Verrucomicrobia sp. and Bacillus aryabhattai, and depressed the species of Ralstonia sp., Chryseobacterium gleum, Fluviicola taffensis, Enterobacter sp. and Bacillus megaterium. These results confirmed that the continuous application of BIO effec- tively controlled the fusarium wilt disease, improved the crop yield and fruit quality, and modulated the soil cuhurable microflora under field condition.