Preparation Of Antagonistic Bio-organic Fertilizer And Its Effect On Disease Resistance And Growth Promotion Of Camellia Oleifera Seedlings And New Afforestation

Camellia oleifera,as a unique woody oil crop in my country,has huge economic value,edible value,medicinal value and environmental value.However,with the increase in the variety of C.oleifera diseases and the increasing damage,the emergence of large areas of C.oleifera low-yielding forests has a certain impact on the development of the C.oleifera industry.During the transformation of C.oleifera low-yielding forests,the largescale and unscientific application of chemical fertilizers has caused a series of resource and environmental problems such as serious water pollution,air pollution,and soil degradation,the use of organic fertilizers alone has relatively few nutrients,resulting in large dosages and insignificant short-term effects.Therefore,microbial organic fertilizers,as an environmentally friendly fertilizer with both microbial fertilizer and organic fertilizer effects,have become a green and sustainable development of the C.oleifera industry an important measure.In this study,the new afforestation of annual C.oleifera and perennial C.oleifera seedlings in Hainan Keda Forestry Co.,Ltd.,Chengmai County,Hainan Province were used as the research objects.The functional bacteria were comprehensively identified by morphology and 16S rDNA molecular sequencing,the growth curve of the functional strains was determined and the antagonistic relationship between the functional strains was observed by the cross method,and the compounding and sampling of the functional strains were carried out,the most suitable type of organic fertilizer,water content and bacterial liquid inoculum were selected to prepare C.oleifera antagonistic microbial organic fertilizer and its quality was tested.The results of this study are as follows:(1)Isolation,screening and identification of functional bacteria in the rhizosphere soil of C.oleiferaFrom the rhizosphere soil of C.oleifera,33 culturable nitrogen-fixing bacteria,61 phosphate-solubilizing bacteria and 41 potassium-solubilizing bacteria were screened out,among them,the strain N-27 has the highest nitrogen fixation capacity,with a nitrogen fixation capacity of 103.75 mg/L;the phosphorus solubilizing bacteria strain P-01 has a higher phosphorus solubilization effect than other strains,the phosphorus dissolution circle ratio D/d reaches 1.91,and the phosphorus solubilization amount reaches 31.34 mg/L;the available potassium content of the potassium-solubilizing bacteria strain K-12 reached 19.97 mg/mL,and the relative increase of potassium ions reached 21.77%.Among the strains initially screened,nitrogen-fixing bacteria have no antagonistic effect on the main diseases of C.oleifera,while Phosphorus solubilizing bacteria P-01 and strain P-30 have antagonistic effects on C.oleifera anthracnose pathogens and soft rot pathogens;One strain K-12 has antagonistic effect on C.oleifera anthracnose pathogen,and all three strains have the ability to produce IAA.Molecular identification results showed that the nitrogen-fixing bacteria N-27 is the closest relative to Enterobacter chengduensis,the phosphate solubilizing bacteria P-01 is the most closely related to Burkholderia contaminans,and the potassium solubilizing bacteria K-12 is the most closely related to Burkholderia cepacia.(2)Preparation of C.oleifera antagonistic bio-organic fertilizerThe results of the strain growth curve showed that nitrogen-fixing bacteria N-27 entered the logarithmic phase faster than the other two strains,the growth curves of potassium-solubilizing bacteria K-12 and phosphate-solubilizing bacteria P-01 tended to be similar,and the overall bacterial concentration was slightly lower than that of strain P-01,sampling and inoculation were carried out at the logarithmic phase of the three strains and about 20 h when the bacterial concentration was equivalent.The results of the crossstriking method showed that the colonies at the intersections of the lines between the two functional strains grew well,and the three functional strains could be compounded for subsequent experiments.The results of pot experiment and the determination of the number of viable bacteria of different combinations of C.oleifera antagonistic bio-organic fertilizers showed that the compound bacterial solution of three functional bacteria was mixed with type C organic fertilizer and the combination of glutathione was added.The optimum inoculum amount of the functional bacterial solution mixed with the fertilizer is 20%,and the optimum water content of the organic fertilizer is 20%.Within 6 months,the number of viable bacteria of the C.oleifera antagonistic biological organic fertilizer has been maintained at 2 × 108,and there is no pollution and mildew occurrence,which meets the requirements of the "Microbial Fertilizer"(NY227-94)standard.(3)Fertilizer effect of C.oleifera antagonizing bio-organic fertilizerThe C.oleifera antagonistic bio-organic fertilizer has a certain promoting effect on the growth of C.oleifera,and the disease incidence and disease index of C.oleifera are significantly reduced,and the control effects on C.oleifera perennial seedlings and new afforestation diseases are 60.78%and 41.66%respectively.It can effectively inhibit the occurrence of C.oleifera diseases.Experiments show that C.oleifera antagonistic bioorganic fertilizer can increase soil nitrogen,phosphorus and potassium content and soil enzyme activity to improve C.oleifera soil environment,while C.oleifera leaves increase phenylalanine ammonia lyase(PAL)and peroxidase(POD)activities,the resistance of C.oleifera increased.