| Blueberry root rot have occurred in southeast of Guizhou(Huangping,Danzhai and Majiang),south of Guizhou and southwest of Guizhou.And use of biological control to control the blueberry root rot can effectively reduce the amount of the use of chemicals and ease of the resistance of pathogens.In this paper,taking blueberry root rot for target pathogens,the content of the following:1.Identified the pathogenic fungus of blueberry root rotAccording to Koch's rule,determined the pathogenic strains(50)separated from Bluebery's root.Based on the morphological characteristics,identified the pathogenic strains by Booth's Fusarium spp.classification system(Booth,1971)and the fungus mycology of plant pathogenic(Zhang,et al.,1986).The results show that: In 28?,Fusarium oxysporum cultivated 5 d on PDA,the colony average diameter is 7.61 cm,assumes the circular,pink-and-white or light pink,with purple,protuberant flocculent,colony back with pale purple,aerial hyphae,white cotton wool shaped.Ten days later,there are many small conidia,colorless,a kidney or ovoid,0-1 diaphragm,7.4~16.3?m×3.3~5.0 ?m.Large conidia,colorless,sickle shape,2-5 diaphragm,most of them are 3 diaphragm,at both ends of the cells are slightly pointed,16.3~29.9 ?m×2.1~7.7 ?m.Easy to produce chlamydospore,spherical or near spherical,slender mycelium,bottle shape.Compared the sequence of ITS with the r DNA of the known strains in Gen Bank,the results showed that the homology of the Fusarium oxysporum was 100%.In combination with morphological and molecular biological identification,50 pathogenic strains of blueberry root rot were Fusarium oxysporum.2.Determination of inhibitory rate and identification of the biocontrol strains of blueberry root rotMicroorganisms were separated from soil of blueberry root by dilution method.With the target fungi of blueberry root rot(Fusarium oxysporum),we used the method of confrontation to obtain 14 antagonistic strains of blueberry root rot(2 strains of fungi,10 strains of bacteria and 2 strains of actinomycetes).Their inhibition is stable.the inhibition effect of biocontrol bacteria is really better(83.89%),and followed by actinomycetes,the inhibition effect of biocontrol fungi is really worse(60%~73%).The study observed morphological characteristics,physiological and biochemical test,and analysed the sequence of 16 sr DNA of those biocontrol strains to identify them.The result of identification showed:2 biocontrol fungi belong to the Penicillium,M-1 was Penicillium janthinellum,M-8 was Penicillium adametzii.10 biocontrol bacterium belong to the Bacillus,B-2 and B-10 were B.amyloliquefaciens,B-3 was B.amyloliquefaciens subsp,B-4 was the B.subtilis,B-5 and B-6 were B.siamensis,B-7was B.velezensis,B-8 was B.tequilensis,B-9 was B.subtilis subsp.2 biocontrol actinomycetes belong to the Streptomyces,S-1 and S-2 were Streptomyces hygroscopicus.3.Determination of pot experiment of biocontrol strains of blueberry root rotThe result of pot experiment of biocontrol strains(M-8,M216-2,B-6,B-7,B-10 and S-1)of blueberry root rot showed: the control effection of B-6 was the best(70%),and the control effection of M-8 was worst(30%).The control effect of M216-2 was higher than other treatments,except for B-6,B-7 and S-1.In this study,the result of pot experiment of three biocontrol strains(M216-2,B-6and S-1)of blueberry root rot showed:the control effection of C-1(M216-2+B-6)and C-3(B-6+S-1)were the best(80%),and were higher than M216-2(50%),B-6(70%)and S-1(60%).While the control effection of C-2(M216-2+S-1)(40%)was worse,and was lower than M216-2 and S-1.In this study,the result of pot experiment of three biocontrol strains(M216-2,B-6and S-1)of blueberry root rot showed:the control effection of D(M216-2+B-6+S-1)was really well(70%).The control effection of D was higher than C-2(40%),and was lower than C-1 and C-3.In different methods of treatment,different time treatment,the control effect were significantly different,and the control effect of treatment 1 and treatment 2 were the best. |
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