Screening,Identification And Application Of Antagonist Against Tobacco Black Shank

Tobacco black shank is serious harmful disease that spreading through soil,screening anti microbial that has the good prevention effect to tobacco black shank and applied to production practice has the great significance to tobacco safety production.Isolation and screeninged antagonistic test in Tobacco Research Institute of Shandong during June to October 2014,The pot and field and antagonistic antibiotic fermentation conditions optimization experiments were did in Henan Agricultural University Campus in Xuchang modern tobacco agriculture science and Technology Park during November 2014 to 2015 August.the main research results are as follows:1?Isolation screening and identification of antagonistic against tobacco black shankDigged the rhizosphere soil that without tobacco plants disease from black shank disease of high incidence in tobacco field,screened antagonistic against tobacco black shank with the Phytophthora nicotianae were WZL-072 that were screened in our own laboratory,we get 26 antagonistic bacteria strains in pure culture,8 antagonistic fungi strains of pure culture from initial screened.One antagonistic fungi YCG-2 with high inhibition rate were obtained by the plate confrontation experiment,the inhibition rate reached 84.34%,and 6 antagonistic bacteria strains had higher inhibition rate,and the inhibition rate between 77.27% to 67.42%.Through the inhibitory rate of the highest fungal YCG-2 of morphological and molecular identification,the phylogenetic relationships of the strain was identified and Trichoderma Trichoderma harzianum Trichoderma harzianum is near,and morphological and culture characteristics and Trichoderma harzianum consistent.So,identified it as.Trichoderma harzianum.2?Effect of strain YCG-2 combined with high carbon remediation to soil fertilizer agains tobacco black shankWith spore suspension dipping root method to study YCG-2 strains with applied high carbon based soil remediation fertilizer on tobacco black shank pot control effect,the test results show that: high carbon based soil remediation fertilizer on tobacco black shank has better control effect for the YCG-2 strains.The disease index of YCG-2 treated with 28.33 b was,and the disease index of control treatment was 66.67,and the control effect was 57.45%.Test at the same time to carry out the high carbon based soil remediation fertilizer and spores of YCG-2 liquid combination process test,results show that: Gao Tanji remediation of soil fertilizer and YCG-2 spore suspension with application of smoke processing plant disease index was 25.Only in the application of high carbon base soil repair fertilizer of tobacco plant disease index was 62.5,control effect 60.01%.And only applying YCG-2 the spore suspension of tobacco plants compared to the increasing application of high carbon based soil remediation fertilizer processing control effect increased,but no significant difference was observed between the two,indicating that increasing nitrogen fertilizer of high carbon based soil remediation prevention ability of tobacco black shank on the strain of YCG-2 improve not obviously promote role.3?Effects of Effect of strain YCG-2 combined with high carbon remediation to soil fertilizer to the growth of tobacco plants in the fieldStudy on the effect of applying high carbon based soil remediation fertilizer on the growth of tobacco plants in the field of YCG-2 by using spore dip,root irrigation and foliar spraying.The results showed that the YCG-2 strains applied high carbon base soil repair of fat cell tobacco mosaic disease incidence and disease index were4.94%-5.76%,2.88-3.70,tobacco red star disease incidence and disease index respectively,0.82-0.89 3.02%-3.29%,compared to the control treatment two diseases incidence rate of disease index 22.99%,4.24% and 15.51,1.50,incidence and disease index of greatly reduced.So YCG-2 strains of combined application of high carbon based soil remediation fertilizer can effectively reduce the incidence and disease index of tobacco mosaic virus?TMV?and Alternaria alternata,that YCG-2 strains spore suspension on tobacco plant growth mainly through inhibition of root infection by microbial activity,promote the development of root system is good to improve the tobacco plant nutrition resistance.And root irrigation and irrigation no significant differences in the effects of tobacco plant disease index between root and foliar treatment,indicating that YCG-2 strains of spore suspension applied way of tobacco plant disease index had no effect,foliar application of YCG-2 strains of spore solution and not enhanced its ability to reduce the field diseases.YCG-2 strains with high carbon based soil remediation fertilizer can promote the tobacco plant growth and development,the tobacco plant height,leaf number,maximum leaf area,section spacing,stem girth has obvious role in promoting,the tobacco plant height increased 20-30 cm,leaf number increased 2-3 tablets,maximum leaf area increased by about 500cm²,section spacing increased 1 cm or so,stem girth increased 2-3 cm;YCG-2 strains with biochar with application can increase tobacco plant,root,stem and leaf dry matter accumulation,leaf chlorophyll a,chlorophyll b,carotene content,but the effect is not obvious.The effect of irrigation on the above traits was not significant,and the effect of leaf spraying on YCG-2 was not significant.Therefore,it could not promote the growth of tobacco plant.4?The fermentation conditions optimization of YCG-2 strainThrough the fermentation conditions optimization of single factor test fermentation as per 500 ml bottle of 20 g mushroom residue and ratio of material to water to 1:3.0,inoculum size 1 x 10⁷ cfu·g^-1,p H7.0,28?,constant temperature and humidity culture box 6 days of culture condition of YCG-2 strains of optimal.Spore production conditions orthogonal test showed that in charge of 20 g mushroom residue,culture temperature of 28 degrees,feed water than 1:3.0 conditions,YCG-2sporulation of most average spore yield was 40.18 x 10⁸ cfu·g^-1.Conclusion: we get one antagonistic strain YCG-2 resistance tobacco black shank screened from tobacco rhizosphere soil with the Phytophthora nicotianae were WZL-072 that were screened in our own laboratory.We indentified it as Trichoderma harzianum through morphological and molecular identification.Pot experiment showed that the YCG-2 applying fertilizer of high carbon based soil remediation of black shank control effect reached 60.01%.Field test showed that YCG-2 Shi high carbon based soil remediation fertilizer can effectively reduce the incidence and disease index of tobacco mosaic virus?TMV?and Alternaria alternata,promote the growth and development of tobacco plant.Fermentation condition optimization experiments showed that the optimum culture conditions of YCG-2 strain are follow as: 28?,pH7.0,the ratio of material to water is 1:3.0.