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Study On UV Induced Mutation Of Metarhizium Anisopliae MA4 And The Solid Fermentation

Posted on:2008-05-09Degree:MasterType:Thesis
Country:ChinaCandidate:T W XuFull Text:PDF
GTID:2143360215973395Subject:Crop Genetics and Breeding
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Based on the understanding of control strategies on Brontispa longissima all over the world, the study on the entomopathogenic fungus, Metarhizium anisopliae was summarized.The contents including the aspects are as follows: the study on Metarhizium anisopliae, general situation was expatiated with five aspects, taxonomy and systematic research of Metarhizium; aggressive and pathogenic mechanism, induced mutation for microbial breeding to enhance virulence of M.anisopliae, production of M.anisopliae; expatiated that how to identify formulation, and the present study on M. anisopliae oil formulation all over the world. The compatibility between Metarhizium anisopliae and chemical pesticide were studied on Metarhizium anisopliae .The purpose was to find the weaknesses of Metarhizium anisopliae as a biological insecticide and provide a scientific basis for the large-scaled industrialized production of Metarhizium anisopliae.In this paper, studied on Metarhizium anisopliae MA4. The carbendazim resistant mutants of Metarhizium anisopliae MA4 were generated in the laboratory by UV.The resistance to carbendazim was investigated in different mutations. The mutants could grow well by asexual reproduction in PPDA and could also grow at the concentration of 600ug/ml MBC, but the sensitive strain (MA4) only could grow at the concentration of 5ug/ ml MBC. The study results showed that the mutants'carbendazim-resistant enhanced 1,20 times and could be steadily past down by asexual reproduction. And the ANOVA results demonstrated that the strains of MA4,MA4-30, MA4-34 and MA4-37 chitinase activity had no significantly different.The mutant strain MA4-37 was chosen to develop for mycelium production of Metarhizium anisopliae in submerged culture. The biomass fits well to a logistic growth model at a gaven temperature. Based on observation and modeling, the optimal culture temperature, and harvesting and inoculating time were 28℃and 72h . The solid compost of Metarhizium anisopliae MA4-37 was studied. The results showed that the sporulation in liquid media with 30% of the solid media was the best. A,B,C and F were the best four prearations. The improvement of culture methods showed that the sporulation was higher in shallow plate than in bag。The reason might related to the ventilation. The productive methods of Metarhizium anisopliae MA4-37 were also simplified,the results would benefit to the popularization and application of Metarhizium anisopliae.A modified technology for production of high-quality coidia powder on low-quality rice substrate. Low-quality rice used as solid substrate was tested to produce aerial conidia of Metarhizium anisopliae MA4-37 in shallow plate. The thickness of rice layer piled in dishes, and the source and concentration of supplemented nitrogen were round affectin conidial yield, viability, and water content. The result indicated that, has thickness in the tray is 1.5cm solidmedium production spore powder content is lowest.Adding a very small amount of peptone, KN03 or NH4N03 to the rice substrate significantly increased conidial yield and viability, but there was little difference among the nitrogen sources tested. In an expanded experiment, each gram of rice yielded a maximal conidial powder of 42.1 mg, equivalent to 4.2×1011 conidia. The powdery product was in high quality with pureness of 1.2×1011 conidia/g, viability of 98.3%, and water content of 11.2%. The results indicate that the low-quality rice can be utilized for efficient production of high-quality Metarhizium anisopliae conidia for microbial control of insect pests.The effects of 8 kinds of chemical pesticides to the growth mycelial and germination showed that all the 8 chemical pesticides inhibited them to a certain degree .The higher concentration was,the stronger inhibition was. The correlation was linear. Based on the tests, Metarhizium anisopliae MA4-37 could be used with Bt and Mieyouniao No.3 in certain concentration.It may be worth studying further.
Keywords/Search Tags:Metarhizium anisopliae, Ultraviolet mutagenesis, Solid ferments, Sporulation, Pesticide, Compatibility
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