ABSTRACT
Taking banana continuous planting soil with high banana fusarium wilt disease incidence as a test site, we examined the effect of lime and ammonium carbonate fumigation coupled with bio-organic fertilizer on the suppression of banana fusarium wilt disease and the structure and composition of bacterial community, using real-time quantitative PCR and high-throughput sequencing. The results showed that the disease incidence was reduced by 13.3% and 21.7% in the treatments of LAOF (lime and ammonium carbonate fumigation coupled with organic fertilizer) and LABF (lime and ammonium carbonate fumigation coupled with bio-organic fertilizer), respectively, compared with OF (application of organic fertilizer without fumigation), while the copy number of Fusarium was decreased by 22.4% and 33.0%, respectively. Compared with non-fumigation treatment, lime and ammonium fumigation coupled with different fertilizer applications significantly reduced bacteria richness and diversity, with different community structure, while fumigation had a decisive effect on bacterial community composition. Bacterial richness and diversity of LABF were lower than those of other treatments, while microbial community structure was clearly disparate from other treatments. Compared with non-fumigation treatment, the relative abundance of Mizugakiibacter, Brucella, and Rhodanobacter were significantly improved in the fumigation coupled with different fertilization treatments. Those three genera in LABF were higher than those in LAOF, with significant differences for the relative abundances of Mizugakiibacter and Brucella. Therefore, fumigation combined with bio-organic fertilizer application could reduce the copy number of pathogen, alter soil bacterial community structure and stimulate beneficial bacteria in the resident soil, and thus reduce the occurrence of banana fusarium wilt.
Subject(s)
Fusarium , Musa , Bacteria/genetics , Calcium Compounds , Carbonates , Fertilizers , Fumigation , Oxides , Plant Diseases , Soil , Soil MicrobiologyABSTRACT
In this study, the population size of soil microbes was determined using plate counting method after the application of lime-ammonium bicarbonate and ammonium bicarbonate fumigation. In addition, biofertilizer was applied after soil fumigation and population of Fusarium oxysporum, Fusarium wilt disease control efficiency and plant biomass were determined in the cucumber and watermelon continuous cropping soil. The results showed that the population of F. oxysporum in cucumber mono-cropped soil fumigated with lime-ammonium bicarbonate or ammonium bicarbonate was decreased by 95.4% and 71.4%, while that in watermelon mono-cropped soil was decreased by 87.3% and 61.2%, respectively compared with non-fumigated control (CK). Furthermore, the greenhouse experiment showed that biofertilizer application, soil fumigation and crop type showed significant effects on the number of soil F. oxysporum, Fusarium wilt disease incidence, disease control efficiency and plant biomass based on multivariate analysis of variance. In the lime-ammonium bicarbonate fumigated soil amended with biofertilizer (LFB), significant reductions in the numbers of F. oxysporum and Fusarium wilt disease incidence were observed in both cucumber and watermelon cropped soil compared to non-fumigated control soil applied with organic fertilizer. The disease control rate was 91.9% and 92.5% for cucumber and watermelon, respectively. Moreover, LFB also significantly increased the plant height, stem diameter, leaf SPAD, and dry biomass for cucumber and watermelon. It was indicated that biofertilizer application after lime-ammonium bicarbonate fumigation could effectively reduce the abundance of F. oxysporum in soil, control Fusarium wilt disease and improve plant biomass in cucumber and watermelon mono-cropping systems.
Subject(s)
Bicarbonates , Cucumis sativus , Fumigation , Fusarium , Biomass , Calcium Compounds , Citrullus , Oxides , Plant Diseases , Soil MicrobiologyABSTRACT
A field experiment was conducted for two years to investigate the effects of different fertilization applications on the suppression of banana fusarium wilt disease, crop yield, fruit quality and culturable 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 banana 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 reduced 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 significantly increased the soil microbial biomass, soil culturable 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 structure and showed highest richness and diversity after 2 years of BIO application. The phylogenetic 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 effectively controlled the fusarium wilt disease, improved the crop yield and fruit quality, and modulated the soil culturable microflora under field condition.
