CN102604856A - Biological control serratia marcescens strain for general tobacco mosaic virus - Google Patents

Abstract

The invention discloses a biological control serratia marcescens strain for a general tobacco mosaic virus. The code name of the strain is 2A2; the strain is preserved in China General Microbiological Culture Collection Center on 7th Sep. 2011; and the preservation number of the strain is CGMCC No.5230. The strain can inhibit the infection of the general tobacco mosaic virus. Biological-control experiments show that the strain can prevent and control the general tobacco mosaic virus. The invention also provides an antagonist polysaccharide obtained from the strain. The antagonist polysaccharide has very high application value in the prevention and control on the general tobacco mosaic virus.

Description

One strain tobacco mosaic viruses biological and ecological methods to prevent plant disease, pests, and erosion serratia marcescens bacterial strain

Technical field

The invention belongs to biological technical field, relate to a strain tobacco mosaic viruses biological and ecological methods to prevent plant disease, pests, and erosion serratia marcescens bacterial strain, this bacterial strain and from this bacterial strain, obtain the antagonism polysaccharide component in the application of tobacco mosaic viruses aspect preventing and treating.

Background technology

The tobacco mosaic viruses disease causes that by tobacco mosaic viruses (Tobacco mosaic virus is called for short TMV) the most significant symptom is to form yellowish green alternate mottled floral leaf, and sick limb edge curls to the back side sometimes.Whole growing all can recur this disease to the land for growing field crops from the seedbed, and sick leaf irregular colour after modulating is even, jealous relatively poor, and quality descends.Tobacco mosaic viruses is distributed widely in each cigarette district of China, is injured heavier with provinces such as Heilungkiang, Jilin, Liaoning, Shandong, Henan, Anhui, Guangdong.Especially in recent years in rising trend by the harm of tobacco mosaic viruses and tobacco cucumber mosaic virus, tobacco potato Y virus mixed infection, sx causes the serious underproduction of vega.Still there is not the special efficacy antiviral agent on producing at present; And Mulvania just found to be lost the vigor that infects very soon by the plant virus juice of bacterial contamination in nineteen twenty-six, and therefore utilizing antagonistic bacterium to suppress infecting of plant virus is one of available strategy of viroses of plant control.

Tobacco is the important cash crop of China, and the major production areas of Flue-cured Tobacco in China is distributed in nearly 900 counties and cities of more than 20 provinces and regions such as Yunnan, Guizhou, Sichuan, Hubei, Hunan, Shaanxi, Henan, Anhui, Shandong, Liaoning, Jilin, Heilungkiang.Wherein, Yunnan Province is the maximum province of China's tobacco planting area.The quality of China's tobacco leaf is improving constantly, and national improved variety area reaches more than 90%, is maximum in the world tobacco producing country.

Tobacco mosaic viruses is the main diseases virus disease on tobacco produces; Its host range is wide; Can infect 30 kind 199 kind of plant (Shew & Lucas, 1991), its independence and resistance are all very strong; The fresh juice that contains virus is diluted to 1,000,000 times and still has virulence, and the passivation temperature of virus is 93 ℃, 10min or 75 ℃, 40d in juice; Do 120 ℃ of processing of sick leaf 30min and still have the vigor of infecting.There is a lot of strains system in tobacco mosaic viruses at nature, and homophyletic does not tie up to and often has cross-protection when successively invading the cigarette strain.Tobacco mosaic virus(TMV) is mainly propagated through the juice friction; Cause lesion tissues such as floral leaf, necrosis, deformity, dwarfing, variable color after the intrusion; Not only cause the tobacco production loss; And making general under the cigarette quality, particularly first-class cigarette ratio and inner quality descend, and account for all tobacco diseases and lose over half.National leaf tobacco production in 2007 the due to illness viral disease output value is lost 44795.08 ten thousand yuan, and the loss of 2008 annual value of production reaches 65174.94 ten thousand yuan.

Antagonistic action between the mikrobe is the foundation of biological pesticide development at the occurring in nature ubiquity.The microbial source antiviral substance is main with bacterium and meta-bolites, fungi and meta-bolites thereof, actinomycetes and meta-bolites thereof.The active substance that antivirus action is arranged that microbial metabolism produces, have activity by force, advantage safely and efficiently.From Microbial resources, screen, after separating, obtain Antiphytoviral materials such as polysaccharide, protein, nucleic acid class, small molecules, become the focus of research; The product of formation that has; In agriculture prodn, play a significant role, especially the development of anti-virus type agricultural antibiotic has obtained breakthrough, is a kind of cytidine(C peptide type microbiotic like Ningnanmycin; Have wide spectrum and restraining effect efficiently, and advantage such as low toxicity, low residue.Cytidine(C peptide type microbiotic one Ningnanmycin (ningnanmyein) that nineteen ninety-five extracts from the fermented liquid of streptomyces noursei Xichang mutation (s.nourseivar.xiehangensis) to Gu Xi etc.; The restraining effect of having duplicated to TMV; Preventive effect is more than 65%; Form 2% Ningnanmycin aqua, obtained interim registration figure in 1997.China increased newly again and had a liking for the skin mycin calendar year 2001, was used for the novel agricultural microbiotic of viral diseases of plants control.

Pay attention to day by day along with global food safety production; Along with people's is to smoking healthy growing interest and attention; Serious day by day along with tobacco Sustainable development and chemical pesticide resistance and pollution problem, biological pesticide more and more comes into one's own, and becomes the major portion of integrated control.The biological pesticide selectivity is strong, to the person poultry safety; Pollution-free, to ecological environment security; Effective, the control phase is longer; Of a great variety, development and utilization measure is many.Biology and the sub-preparation agricultural chemicals of chemi-excitation with evoking tobacco resistance is based on the novel agrochemical of inducing enhancement of plant disease resistance, resistance and developing, and product safety is nontoxic, can not cause the resistance of plant; Plant there is remarkable disease-resistant yield-increasing effect; Simultaneously can improve the quality of crop, produce and can reduce or do not use chemical pesticide, the product of production can reach the requirement of green product and Organic food; Particularly in nuisanceless leaf tobacco production, will play an important role; Meet of the requirement of current China, help improving quality of tobacco, increase farmers' income quality of tobacco; Have the boundless market outlook and the good market competitiveness, have comprehensive benefit preferably.Have the biology of induction of resistance and the important content that the sub-biological pesticide of chemi-excitation will become the 21 century agricultural sustainable development, have very wide application prospect.

The Plant diseases biocontrol bacteria of successful Application has some bacterial strains that Agrobacterium, Bacillus, Pseudomonas, Erwinia, Xanthomonas etc. belong at present.An important mechanisms of biocontrol bacteria controlling plant diseases incidence and development is to produce antagonistic substance; Roughly comprise following several types: bacteriocin (bacteriocins), resorcinolphthalein (fluorescein), agrocin (agrocin), aldehydes matter, polypeptide antibiotics (polypeptides), protein-based etc. play a part crucial in biocontrol of plant disease.The antagonistic substance kind that is produced by biocontrol bacteria is many, and the reach wide spectrum can be produced by the various bacteria bacterial strain with a kind of antagonistic substance, and also can produce the antagonistic substance of multiple different structure with a kind of bacterial isolates.

The research and development of biological pesticide at present on the basis of original microbial preparation exploitation, develop to new function, molecular designing or reorganization biological pesticide direction.Microbial pesticide is to utilize mikrobe or its metabolite as the biotechnological formulation of the agriculture objectionable impurities of control, mainly comprises microbial bactericide, microbial pesticide and microbial herbicide.Microbial pesticide comprises entomiasis indigenous bacteria, insect viruses, entomomycete, entomopathogenic nematode and microsporidium.The research that microbial herbicide China is used for the weeds biological control with fungi first is to utilize anthrax " Shandong is protected No. one " control soybean South Dodder Seed Chinese Dodder Seed in 1963; Campelyco after 1966 " Shandong is protected No. one " is generalized to more than 20 provinces in the whole nation, and control effect is stabilized in more than 80%.In the living microorganism weedicide, account for the largest percentage with fungi, the research and development of mycoherbicide is the most active.The U.S. has successfully developed the Colletotrichum gloeosporiodes that is used to prevent and treat crop bacterium phase weeds such as water paddy and wheat class; The black rot of Co., Ltd. of Japan Tobacco exploitation is used to prevent and treat weeds annual bluegrass and bent grass in the lawn, does not use but still there is scale at present.The microbial metabolites of harmful organisms such as agricultural antibiotic mainly refers to be used for anti-ly to cure the disease, worm, grass can be divided into microbiotic, desinsection is plain and kills grass plain.The agricultural antibiotic of exploitation anti-plant viral disease: agricultural antibiotic becomes the focus of various countries' research because of it has that systemic activity is strong, safety, low toxicity, plurality of advantages such as efficient, quick-acting, and who at first succeeds in developing, and who has just grasped the initiative in market.Therefore, exploitation anti-virus type agricultural antibiotic is extremely urgent.From plant, obtain the natural anti-virus material: from herbal medicine, developed some effective anti-virus formulations at present, and on filtering mode, also had breakthrough.Further research and development brings new life will for the control of virus disease.The exploitation compound preparation: between the multiple anti-virus type biological pesticide or carry out between biological pesticide and the chemical pesticide composite, in the hope of reaching good control effect.

Study the existing anti-virus type agricultural antibiotic mechanism of action, clear and definite its action site, action time, novel antiviral type biological pesticide provides theoretical foundation and research means in order further to develop more efficiently.Understanding antimicrobial antiviral-mechanism short of money is to strengthen the important prerequisite that antagonism bacterium screening criteria was renderd a service and confirmed in the biological and ecological methods to prevent plant disease, pests, and erosion of antagonism bacterium; The antagonism bacterium mainly contains 3 kinds of mechanism of action to plant virus: i.e. inactivation in vitro, restraining effect (comprise suppressing to infect and suppressing and breed), induction of resistance, and wherein remarkable with inactivation in vitro.

Therefore the present invention will explore from the biological control aspect; The short living effective antagonistic strain of screening preventive effect; And its antiviral-mechanism studied; Through conventional and molecular biology approach, utilize these antagonistic bacteriums and antagonistic substance thereof control tobacco mosaic viruses disease that research basis and experiment material are provided in the future.

Rhizosphere, the leaf of plant enclose and other little ecosystem in, antagonistic bacterium extensively exists, and since cultivate convenient, growth cycle is short, have very big potentiality to be exploited as new antagonism bacterium source.

Domestic to the existing report of tobacco mosaic viruses diease occurrence thing control; But most only limiting to screening and the pot experiment stage to biocontrol microorganisms, and it is produced the domestic not further investigation as yet in many aspects such as diseases prevention mechanism of extraction, physio-biochemical characteristics and the biocontrol microorganisms of antimicrobial substance.

Summary of the invention

The objective of the invention is to overcome the above-mentioned deficiency of existing in prior technology; And a strain tobacco mosaic viruses biological and ecological methods to prevent plant disease, pests, and erosion serratia marcescens bacterial strain is provided; Be used for the sick biological control of tobacco mosaic viruses, the control sick for tobacco mosaic viruses provides new Microbial resources.

Its technical scheme is:

Bacterial strain according to the invention separates acquisition from Jimo test farm, Qingdao, vega soil sample, identify that the 2A2 bacterial strain is serratia marcescens (Serratia marcescens).The culture condition of this bacterial strain is 28 ℃, LB substratum, pH7.0.This bacterial strain was an enterobacteriaceae, and serratia, bacterial strain code name are 2A2, and this bacterial strain is preserved in China Committee for Culture Collection of Microorganisms common micro-organisms center on September 7th, 2011, and culture presevation number is CGMCC No.5230.

The method of the invention may further comprise the steps:

1) with activatory 2A2 inoculation in the LB substratum, 28 ℃ of constant temperature, 140rpm shaking culture 48h, 4 ℃, the centrifugal 10min of 12000rpm removes thalline, processes the fermented supernatant fluid of the outer metabolite of born of the same parents;

2) every 1ml supernatant adds 1.5ml 95% ethanol, 2.5mg CaCl ₂, evenly stir the back and produce deposition, 3000rpm, 5min is centrifugal, gets deposition and is dissolved in the suitable quantity of water;

3) repeating step 2) the deposition absolute ethyl alcohol that is produced is produced deposition, the sterilized water dissolving is polysaccharide crude.

Beneficial effect of the present invention:

The biological and ecological methods to prevent plant disease, pests, and erosion serratia marcescens bacterial strain 2A2 that the antagonism tobacco mosaic viruses that the present invention obtains is sick; Can be applicable to the control sick to tobacco mosaic viruses; Adopt the withered spot host's of inoculation biology mensuration to show; Its fermented liquid is 98% to the inhibiting rate of TMV, and 2A2 bacterial strain excretory antagonistic substance can be used 95% ethanol and CaCl ₂Extract, 50 times of inhibiting rates to TMV of polysaccharide dilution are 90.0%.10 times of restraining effect to TMV of the Dilution for powder of serratia marcescens production can reach 95%.2A2 bacterial strain excretory antagonistic substance has external passivation, suppresses the effect infect and breed TMV.Has actual using value.

Description of drawings

Fig. 1 is 2A2 fermented liquid (1x10 ⁸Cfu/ml) the withered spot to TMV suppresses design sketch;

Fig. 2 is that the 2A2 polysaccharide crude suppresses symptom figure to the withered spot of TMV;

Fig. 3 is bacterial strain 2A2 plate streaking figure;

Fig. 4 is the thalli morphology figure of bacterial strain 2A2 under transmission electron microscope.

Embodiment

Below in conjunction with concrete and embodiment method of the present invention is done explanation in further detail.

Embodiment 1,

1, the screening of 1 control TMV antagonistic bacterium 2A2 bacterial strain

Picking purifying inoculation is in the LB liquid nutrient medium; 28 ℃ of constant temperature, 140rpm shaking culture 48h, get 40 times of TMV juice of 20ml and equal-volume mixing 15min after; The withered spot host of frictional inoculation TMV three lives-NN cigarette; 2 leaves in every strain inoculation top are mixed into contrast with sterilized water and TMV, and 3～5d investigates withered spot inhibiting rate.There is the bacterial strain of antagonistic activity to adopt the same procedure repeated test through preliminary test, every processing 3 strains, three repetitions.

The investigation of withered spot inhibiting rate shows that bacterial strain 2A2 is best to the inhibition effect of TMV, and the withered spot inhibiting rate of TMV is reached 98%, and biocontrol bacteria has produced in the growth metabolism process has the antibiotics that suppresses virus activity.(seeing table 1)

Withered spot inhibiting rate calculation formula:

Table 1 bacterial strain 2A2 is to the restraining effect of tobacco mosaic viruses

1,22A2 strain fermentation supernatant and polysaccharide are to the restraining effect of TMV

The extraction of fermented supernatant fluid and exocellular polysaccharide

With activatory 2A2 inoculation in the LB substratum, 28 ℃ of constant temperature, 140rpm shaking culture 48h, 4 ℃, the centrifugal 10min of 12000rpm removes thalline, processes the fermented supernatant fluid of the outer metabolite of born of the same parents.

Every 1ml supernatant adds 1.5ml 95% ethanol, 2.5mg CaCl ₂, evenly stir the back and produce deposition, 3000rpm, 5min is centrifugal, gets deposition and is dissolved in an amount of sterile distilled water.Repeat above-mentioned steps, the deposition that is produced is used the small amount of aseptic dissolved in distilled water, be polysaccharide crude.

The outer raw sugar of fermented supernatant fluid and born of the same parents detects TMV is active

Get fermented supernatant fluid and polysaccharide crude liquid, dilute respectively 1x, 10x, 50x, 100x respectively with 40 times of TMV of equal-volume virus juice mixings 15min, inoculate three lives NN cigarette, be mixed into contrast with sterilized water and equal-volume TMV, detect its withered spot inhibiting rate.

Table 22A2 fermented supernatant fluid dilution back is to the restraining effect of TMV

2A2 fermented supernatant fluid (1x) suppresses to see Fig. 1 to the withered spot of TMV.

Can know that from table 2 2A2 strain fermentation supernatant dilution back is respectively 96.8%, 65.0%, 58.0% to the withered spot inhibiting rate of TMV, and do not connect bacterium LB substratum there is not restraining effect hardly in TMV.

The polysaccharide crude that table 32A2 extracts is to the restraining effect of TMV

The 2A2 polysaccharide crude suppresses symptom to the withered spot of TMV and sees Fig. 2.

Embodiment 2

1.1 the practical application of antagonistic bacterium 2A2 on producing

(1) bacterial strain 2A2 pulvis is produced

With 2A2 fermented liquid (1x10 ⁸Cfu/ml) with 6ml: the ratio of 1g is mixed with WHITE CARBON BLACK, stirs, and dries in ventilation illumination place, forms pulvis.With air dried Dilution for powder 10X, 50X, 100X; Adopt half leaf method be inoculated into the three lives-carry out biological experiment on the NN cigarette; Pulvis and the viral mixed solution of equivalent with dilution are processing, are mixed into contrast, the viral effect of detection inhibition with the viral juice of sterilized water and equivalent.

Table 4 dilution pulvis is to the inhibition effect of virus

Behind the Dilution for powder, the effect of good restraining virus is arranged.Pulvis can overcome the difficulty of transportation, is prone to preserve the use of being convenient to produce.

(2) contrast of bacterial strain 2A2 and other antiviral agent effects

Choose to produce and go up the viral inhibitors that often uses: Ningnanmycin (200x), Moroxydine second copper (400x), with the contrast of 2A2 antiviral effect.Every kind of viral inhibitors and 40 times of viral juice uniform mixing 15min are mixed into contrast with sterilized water and TMV, half leaf method be inoculated into the three lives-the NN cigarette on, 2 leaves in every strain inoculation top, every processing 3 strains repeat for three times, 3～5d investigates withered spot and suppresses.(table 5)

The disease resisting effect of many kinds of viral inhibitors of table 5

(3) to the disinfection of scissors

The sterilization scissors in 40 times of TMV juice, soak 1min, after the taking-up respectively 1. following～4. soak 30sec in the liquid, on common cigarette NC89 of 5～6 leaf phases, cut 3 leaves in top.Every processing 8 strains, 3 repetitions.30d investigates disease index.1. 2A2 fermented liquid, 2. LB substratum, 3. 4. clear water does not soak, and directly cuts the NC89 blade.

The disinfection that table 62A2 fermented liquid is cut leaf-cutting

Find out that by table 6 scissors is immersed in the TMV juice, picked viral juice; In the 2A2 fermented liquid, soak, can kill overwhelming majority virus, sickness rate is merely 0.46%; Disease index is also far below other processing, therefore, produces and can operating apparatus such as cut with the leaf-cutting of sterilizing of 2A2 fermented liquid.Also observe the processing that is immersed in LB substratum and the clear water in the test, sickness rate also is lower than the processing of 4. not soaking, and is because diluted the virus concentration that picks on scissors, has reduced invasiveness.

1, the classification position Molecular Identification of 22A2

Reference literature (Lin Wanming edits bacteria molecule genetic classification authentication method [M]. Shanghai; Shanghai science tech publishing house 1990) method is extracted overall dna; The pcr amplification reference (the C.W. Dieffenbacher, G.S. moral Vicks VapoRub is reined in work, and Huang Peitang etc. translate .PCR experimental technique experiment guide [M]; Beijing science tech publishing house, 2000) method is carried out.With 2A2 thalline genomic dna is template; Through PCR reaction amplification; Detect through 1% agarose gel electrophoresis, obtain the above specific fragment of a 1.0kb, measure this fragment sequence (the PCR product is by the big-and-middle living bio tech ltd order-checking of Beijing China); The result shows that recording the 2A2 bacterial strain is 1026bp.Submit the 16s rDNA complete sequence that records (seeing appendix SEQ ID NO1) to GenBank (www.ncbi.nlm.nlh.gov); BLAST software and the DNAMAN software used are wherein analyzed; Find that the sequence that the 2A2 bacterial strain records is identical with serratia marcescens 16s rDNA partial sequence.Therefore identify that the 2A2 bacterial strain is serratia marcescens (Serratia marcescens).Simultaneously 2A2 is landed Genbank, the number of landing is FN812753, and phylogenetic tree shows 2A2 and serratia marcescens homology 98%.

The research of 2 bacterial strain 2A2 Physiology and biochemistries

Bacterial strain 2A2 plate streaking is seen Fig. 3.

The bacterium colony of bacterial strain is protruding basically, and the center is opaque, and the edge is irregular, and size is 1～2.5mm, all produces red pigments.

The thalli morphology of bacterial strain 2A2 under transmission electron microscope seen Fig. 4.

The fresh culture thing of serratia marcescens is got by negative staining preparation of specimen, makes with saline water, and evenly suspension adds one and drips on the copper mesh film carrier, 1% phospho-wolframic acid negative staining.

The negative staining sample is used the H-600 transmission electron microscope, under acceleration voltage 75KV, observes.Stagnation point is observed.

The cell polydisperse of serratia marcescens exists, and does not have the regularly arranged of two or chaining, is direct rod shape,, the blunt circle in two ends.Size is 0.62～0.87x0.87x1.1～2.3um.Accidental visible filament.Cell has tangible all flagellums and dense pili, and figure does not see significant pod membrane.

Attach: nucleotide sequence involved in the present invention

SEQ ID NO1 (2A2 bacterial strain 16S rDNA complete sequence):

TTACaCATGCAAGTCGAGCGGTAGCACAGGGGAGCTTGCTCCCTGGGTGACGAGCGGCGGACGGGTGAGTAATGTCTGGGAAACTGCCTGATGGAGGGGGATAACTACTGGAAACGGTAGCTAATACCGCATAACGTCGCAAGACCAAAGAGGGGGACCTTCGGGCCTCTTGCCATCAGATGTGCCCAGATGGGATTAGCTAGTAGGTGGGGTAATGGCTCACCTAGGCGACGATCCCTAGCTGGTCTGAGAGGATGACCAGCCACACTGGAACTGAGACACGGTCCAGACTCCTACGGGAGGCAGCAGTGGGGAATATTGCACAATGGGCGCAAGCCTGATGCAGCCATGCCGCGTGTGTGAAGAAGGCCTTCGGGTTGTAAAGCACTTTCAGCGAGGAGGAAGGTGGTGAACTTAATACGCTCATCAATTGACGTTACTCGCAGAAGAAGCACCGGCTAACTCCGTGCCAGCAGCCGCGGTAATACGGAGGGTGCAAGCGTTAATCGGAATTACTGGGCGTAAAGCGCACGCAGGCGGTTTGTTAAGTCAGATGTGAAATCCCCGGGCTCAACCTGGGAACTGCATTTGAAACTGGCAAGCTAGAGTCTCGTAGAGGGGGGTAGAATTCCAGGTGTAGCGGTGAAATGCGTAGAGATCTGGAGGAATACCGGTGGCGAAGGCGGCCCCCTGGACGAAGACTGACGCTCAGGTGCGAAAGCGTGGGGAGCAAACAGGATTAGATACCCTGGTAGTCCACGCTGTAAACGATGTCGATTTGGAGGTTGTGCCCTTGAGGCGTGGCTTCCGGAGCTAACGCGTTAAATCGACCGCCTGGGGAGTACGGCCGCAAGGTTAAAACTCAAATGAATTGACGGGGGCCCGCACAAGCGGTGGAGCATGTGGTTTAATTCGATGCAACGCGAGAACCTTACCTACTCTTGACATCCAGAGAACTTAGCAGAGATGCTTTGGTGCCTTCGGGAACTCTGAGACAGGTGCTGCATGGTCTGTGCACCAATCCATCTCTGCTAAGTTCTCTGGATGTCAAGAGTAGGTAAGGTTCTTCGCGTTGCATCGAATTAAACCACATGCTCCACCGCTTGTGCGGGCCCCCGTCAATTCATTTGAGTTTTAACCTTGCGGCCGTACTCCCCAGGCGGTCGATTTAACGCGTTAGCTCCGGAAGCCACGCCTCAAGGGCACAACCTCCAAATCGACATCGTTTACAGCGTGGACTACCAGGGTATCTAATCCTGTTTGCTCCCCACGCTTTCGCACCTGAGCGTCAGTCTTCGTCCAGGGGGCCGCCTTCGCCACCGGTATTCCTCCAGATCTCTACGCATTTCACCGCTACACCTGGAATTCTACCCCCCTCTACGAGACTCTAGCTTGCCAGTTTCAAATGCAGTTCCCAGGTTGAGCCCGGGGATTTCACATCTGACTTAACAAACCGCCTGCGTGCGCTTTACGCCCAGTAATTCCGATTAACGCTTGCACCCTCCGTATTACCGCGGCTGCTGGCACGGAGTTAGCCGGTGCTTCTTCTGCGAGTAACGTCAATTGATGAACGTATTAAGCTCACCACCTTCCTCCTCGCTGAAAGTGCTTTACAACCCGAAGGCCTTCTTCACACACGCGGCATGGCTGCATCAGGCTTGCGCCCATTGTGCAATATTCCCCACTGCTGCCTCCCGTAGGAGTCTGGACCGTGTCTCAGTTCCAGTGTGGCTGGTCATCCTCTCAGACCAGCTAGGGATCGTCGCCTAGGTGAGCCATTACCCCACCTACTAGCTAATCCCATCTGGGCACATCTGATGGCAAGAGGCCCGAAGGTCCCCCTCTTTGGTCTTGCGACGTTATGCGGTATTAGCTACCGTTTCCAGTAGTTATCCCCCTCCATCAGGCAGTTTCCCAGACATTACTCACCCGTCCGCCGCTCGTCACCCAGGGAGCAAGCTCCCCTGTGCTACCGCTCGACTTGCATGTGTTAAGCCTGCCGCCAGCGTTCAATCTGAGCAGAGAACAAACACTTCCCAA

Claims (4)

1. strain tobacco mosaic viruses biological and ecological methods to prevent plant disease, pests, and erosion serratia marcescens (Serratia marcescens) bacterial strain; The bacterial strain code name is 2A2; This bacterial strain is preserved in China Committee for Culture Collection of Microorganisms common micro-organisms center on September 7th, 2011, culture presevation number is CGMCC No.5230.

2. the application of the said bacterial strain 2A2 of claim 1 in the control tobacco mosaic viruses.

3. one kind obtains the preparation method of antagonism polysaccharide component with the described tobacco mosaic viruses biological and ecological methods to prevent plant disease, pests, and erosion of claim 1 serratia marcescens bacterial strain, it is characterized in that, may further comprise the steps:

1) with activatory 2A2 inoculation in the LB substratum, 28 ℃ of constant temperature, 140rpm shaking culture 48h, 4 ℃, the centrifugal 10min of 12000rpm removes thalline, processes the fermented supernatant fluid of the outer metabolite of born of the same parents;

2) every 1ml supernatant adds 1.5ml 95% ethanol, 2.5mg CaCl ₂, evenly stir the back and produce deposition, 3000rpm, 5min is centrifugal, gets deposition and is dissolved in the suitable quantity of water;

3) repeating step 2) the deposition absolute ethyl alcohol that is produced is produced deposition, the sterilized water dissolving is polysaccharide crude.

4. the application of the described antagonism polysaccharide component of claim 3 in the tobacco mosaic viruses control.

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