| Lily,as the only plant integrating medicinal,ornamental and edible purposes,has a very high economic value;it is mainly grown in Hunan,Shanxi,Gansu and Jiangsu in China.Long-term continuous planting of lilies often leads to continuous cropping obstacles.Lily wilt is one of the most common and most harmful problems.Lily wilt is mainly caused by Fusarium oxysporum sp.Is a devastating disease that seriously affects the yield and quality of lily.The current research.on the prevention and control of Lilium wilt is concentrated on the breeding of disease-resistant varieties and the screening of chemical agents.However,there are difficulties in breed selection and pollution of the environment by chemical agents.Therefore,it is urgent to strengthen the prevention and treatment of Fusarium wilt.Biological control is one of the measures to comprehensively prevent and control Lilium wilt,which is of great significance to maintain the sustainable development of ecological agriculture.In this paper,pathogenic bacteria were isolated from lily plants with typical Fusarium wilt disease in the field,and a strong pathogenic strain-Fusarium oxysporum was obtained by screening and purifying the pathogenic spore suspension;using the pathogenic bacteria as the target bacteria,two highly effective antagonistic bacteria were screened;Combining antagonistic antibacterial and decomposed organic fertilizer to prepare a special bio-organic fertilizer for lily.The field experiment explored the promoting effect of the lily bio-organic fertilizer on lily and the impact of its application on the lily soil microbial flora,with a view to Provide theoretical support for the promotion of lily special biological organic fertilizer in lily planting.The following main research results were obtained:1.Four pathogenic strains of P-OF,P-PF,P-RF,and P-BF were isolated from plants with severe disease of typical wilt disease,and the isolation rates were 25%,20%,10%,and 5%,respectively.The Koch’s Law back-up experiment shows that the incidence of P-OF and PPF is 100%,and the scale disease index is 92.50,48.25,15.00,and 30.00,respectively.Pathogenesis,preliminary determination that the strain P-OF is the most pathogenic;the identification results of the strain P-OF by morphology and molecular biology indicate that the isolated pathogen is Fusarium oxysporum;the incidence of Fusarium wilt It was positively correlated with the concentration of spore suspension of inoculated pathogens.The results of lily scale inoculation experiment and pot experiment showed that the concentration of soil pathogens was 103 CFU·g-1 which was the critical concentration that caused the disease of lily plants.When the concentration of soil pathogens is not higher than 105 CFU·g1.the disease index increases with the increase of inoculation concentration.When the concentration of soil pathogens is higher than 105 CFU·g-1,the disease index no longer increases significantly.2.The pathogenic bacteria of Lilium wilt disease obtained in the previous chapter are the target bacteria.Two strains with strong antagonistic activity(HQWBH1 and HQWBH2),The inhibition rate of pathogens is 63.58%and 58.40%respectively.Both morphology and 16s rDNA identification confirmed that these two strains of antibacterial bacteria were both Bacillus subtilis.By optimizing the cultivation conditions,the optimum culture temperature of the strain HQWBH1 is 30℃,the optimum pH range is 5.7～6.7,the preferred carbon source is glucose or sorbitol,and the preferred nitrogen source is yeast powder or potassium nitrate;the optimal strain HQWBH2 is determined The cultivation temperature is 30℃,the optimal pH range is 5.7～7.7,the preferred carbon source is glucose or sucrose,and the preferred nitrogen source is peptone or yeast powder.The antagonistic strains HQWBH1 and HQWBH2 were mixed with decomposed straw organic fertilizer to make lily-specific bioorganic fertilizer,and the number of effective viable bacteria per gram of fertilizer within 6 months of storage was more than 20 million.Among them,the water content of the HQWBH1 bio-organic fertilizer is 21.2%,the organic matter content is 42.5%,the contents of N,P2O5 and K2O are 3.52%,2.18%and 1.68%;HQWBH2 bio-organic fertilizer has a water content of 22.3%,an organic matter content of 41.4%,and N,P2O5,and K2O contents of 3.31%,2.11%,and 1.62%,respectively.3.The pot experiment results show that the application of compound microbial fertilizer containing HQWBH1 strain can significantly reduce the incidence of Lily wilt disease,and the prevention and control effect reaches more than 77%.The continuous application of compound microbial fertilizer containing HQWBH1 strain can significantly improve the bacteria and bacteria in the lily rhizosphere.The number of actinomycetes significantly reduces the number of fungi and Fusarium oxysporum,improves the microbial flora of the lily rhizosphere soil,overcomes continuous cropping obstacles,and reduces the incidence of lily wilt;Field application of special lily bio-organic fertilizer can significantly increase the yield of lily.Compared with CK(without fertilization),the output of T1(HQWBH1 bioorganic fertilizer)and T2(HQWBH2 bio-organic fertilizer)are better,and the output is 12192.6 k·ha-1 and 11741.3 k·ha-1,increasing yields were 13.9%and 9.65%,respectively;compared with CK,bio-organic fertilizer treatment significantly increased the single bulb weight,and significantly increased plant height,stem thickness and chlorophyll content;field application of biological Organic fertilizer can significantly improve the nutritional quality and functional nutritional indexes of lily.The content of polyphenols in the application of bio-organic fertilizer containing antibacterial HQWBH1 and HQWBH2 increased 1.12 times and 1.08 times respectively compared with CK;polysaccharide content increased 1.41 times and 1.29 compared with CK Times.At the same time,it can significantly increase the number of culturable bacteria and actinomycetes in lily soil,reduce the number of fungi and Fusarium oxysporum,and can increase the soil organic matter content and improve the soil physical and chemical properties.4.Use Illumina MiSeq high-throughput sequencing technology to sequence the CK and BOF(T1)in the field test for the V3-V4 region of the 16s rDNA gene.The results showed that,compared with CK,BOF significantly increased the bacterial diversity and richness index,and significantly changed the soil microbial community structure.BOF treatment significantly increased the relative abundance of eutrophic microbial groups(Copiotroph)in the soil,such as Proteobacteria,Bacteroideles,Firmicule,Gemmatimonadete,etc.,Reducing the relative abundance of Oligotroph groups such as.Acidobacteria and Chioroflexi.CCA analysis showed that the effect of fertilization on soil microbial community was achieved by changing the soil physical and chemical properties.Correlation analysis of soil physical and chemical properties and microbial genus showed that:Gemmatimonas,Sphingomonas and Sphingomonas Nitrosospira has a significant positive correlation with the content of organic matter,ammonium nitrogen and nitrate nitrogen,while the genus Acidobacteria GP3,Thermogutta spp.And Thermogemmatispora spp.Are related to organic matter,ammonium nitrogen It is significantly negatively correlated with nitrate nitrogen content.Regression analysis showed that the Shannon diversity index and Inv-Simpson uniformity index of total soil bacteria were significantly positively correlated with lily yield.Soil Proteobacteria,Verruccomicrobia,Firmicute and The increase in the phylum Bacillus(Geynmatimonadete)is beneficial to the increase in lily production.In summary,the application of special bio-organic fertilizer for lily can improve soil physical and chemical properties,increase the yield and quality of lily,and the application of special bio-organic fertilizer for lily can effectively improve soil microbial community structure and build a more stable microbial flora Lily is stable and highly productive. |
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