Screening And Development Of Seedling Medicine Of Endophytic Antagonistic Bacteria Against Dalbergia Odorifera Anthracnose

Dalbergia odorifera T Chen.is one of the precious tropical native tree species in China.In recent years,due to the large number of planting Dalbergia plantation,plant diseases and insect pests have become increasingly prominent.Anthracnose is one of the main disease of Dalbergia odorifera.At present chemical prevention is the main control method on Dalbergia anthracnose,there is no Antagonistic microorganisms control reports.This thesis is mainly carried out in healthy leaves of Dalbergia odorifera,within the born antagonistic bacteria separation and mutagenesis and for anthracnose control,optimization of fermentation conditions,development of seedling care agent,to provide reference to biological control of Dalbergia odorifera anthracnose and promote seedling growth.The main results are as follows:?1?The screening and identification of antagonistic bacteria against Dalbergia odorifera anthracnose.The healthy leaves of Dalbergia odorifera was collected from Chengmai farm,51 endophytic bacteria strains with bacteriostatic activity were obtained by using dilution-plate method.From flat confrontation method screening and fermentation liquid compound sieve,one endophytic bacteria strain JXYJ1-14^UV was found with inhibitory effect to 78.48%when Colletolrichul gloeosporioides as the indicator fungi.JXYJ1-14^UV was identified as Bacillus amyloliquefaciens by its morphological,physiological and biochemical characteristics as well as 16s rDNA sequence and phylogenetic analysis.Experiments were conducted with JXYJ1-14^UV that was mutated by ultraviolet.The results showed that the inhibition rate of mutation bacteria was increased 18.97%and the maximum inhibition rate reached 93.37%.Genetic stability test results showed that the mutation bacteria JXYJ1-14^UV had good genetic stability.Pot experiment was conducted with the JXYJ1-14^UV biocontrol effect,the results showed that JXYJ1-14^UV of Dalbergia odorifera anthracnose had good effect on Dalbergia odorifera anthracnose,fermentation of JXYJ1-14^UV100 times fluid control effect was more than 65%,and the height of seedlings was 9.97%higher than CK,and the ground diameter had increased 12.52%.?2?The optimization of fermentation medium formula and conditions for Bacillus amyloliquefaciens JXYJ1-14^UV.By single-factor test and orthogonal design,the optimum medium of strain JXYJ1-14^UV was obtained,which consisted of 1%glucose,0.5%beef extract,1%yeast extract and 0.5%NaCl.And the results of single-factor method showed that the initial pH,culture temperature,inoculation quantity,liquid volume,shaking speed and culture time were the key factors to influence the bacterial growth and inhibitory rate of JXYJ1-14^UV.The optimal fermentation conditions was:original pH 7.0,fermentation time 60h,fermentation temperature 38oC,rotation speed 180r/min,inoculum of 0.5%which cultured in 250ml flask with 80ml culture.?3?Development of Dalbergia odorifera medicine.The optimal formulation of WP were confirmed as follows:original medicines 70%,carrier of kaolin 10%,wetting agent dodecyl sodium sulfate 4.5%,dispersion agent sodium lignosulfonate 6.0%,stabilizer polyethylene glycol 1.6%,kaolin was added to 100%.The WP of JXYJI-14^UV can be stored at room temperature 25? and 4?,and can be stored for at least 3 months.By single-factor test and orthogonal experiments,the more effective proportion of four components of the medicine that was composed of 71.88%WP of JXYJ1-14^UV,0.16%gibberellin,11.98%aquasorb,15.97%fungus chaff.Field experiments showed that the control effect of Dalbergia odorifera anthracnose reached 73.98%,Dalbergia odorifera height growth had improved 22.41%,diameter growth had increased 28.12%.