| Because of using of chemical fertilizers for a long time, it has caused decrease of soil fertility and envirommental pollution. Research and application of microbial fertilizer has increasingly recieved to attention of public. Chaetomium globosum ND35 is a dominant endophytic fungus isolated from healthy Populus tomentosa. It has excellent culture characteristic and biocontrol potential. It can not only promote the growth of plants and enhance crop yields, but also control many plant diseases. So it is able to be prepared into microbial fertilizer and be applicated in agriculture production. In this paper, the solid fermentation technology of microbial fertilizer of Chaetomium globosum had been optimized.Its fertilizer efficiency was tested on different crops under the field condition. Effect of soil enzyme activities and the number of microbes of cucumber rhizosphere had been investigated after applying microbial fertilizer of C. globosum. The inhibition mechanism had been studied by the crude extracts from C. globosum ND35 liquid fermentation against Valsa sordida.On the basis of ND35 fertilizer cultivation methods, the best program has been choosed.The rersult showed that the sporulation was influenced by the content of PDB in the nutrient solution and the breathability of microbial fertilizer. In the nutrient solution, the ratio of PDB and water was designed such as 3:2, 4:1, 2:3, 1:4 and 1:1 five gradients. The breathability was set using rope and tampon to tether the bag. The results showed that according to this method that the bag tether with rope and the ratio of nutrient solution with 1:4 produced microbial fertilizer, and the sporulation attained 380 million per gram. This method was the best because of low production cost, simple operation, and low pollution.The Chaetomium globosum fertilizer had been applied and investigated the promoting growth effects on sweet potato, potato, corn, cucumber in the field. The crop growth index and yield was measured. The results indicated that after treatment with ND35 fertilizer, the vine length of sweet potato increased by 6.19% compared with the control, and the stem diameter and yield per plant were increased by 9.24% and 16.12%, respectively. On potato,the yield per plant compared with the control was improved 25.49%. The corn plot yield was increased significantly after treatment with ND35 fertilizer, that was improved 34.23%. In the condition of microbial fertilizer of C. globosum, using at seeding period would work better onincreasing cucumber yield than that at transplanting period. It is not able to use too much when using both at seeding and transplanting period.Cucumber was served as an example, after applying microbial fertilizer of C. globosum,determined soil enzyme activities and the number of soil microbes of cucumber rhizosphere soil at each growth stage. The results showed that the activities of urease, invertase and catalase were increased with different degrees after applying microbial fertilizer, respectively.The highest value appeared in the grain filling stage, and reduced at apoptosis phase. After applying microbial fertilizer, the numbers of soil bacteria and actinomycetes were significantly increased than the control. The number of bacteria reached the highest value in the seedling and flowering period. The number of actinomycetes reached the highest value in the flowering period and grain filling stage. But the number of fungi only increased rapidly in the flowering period, and later decreased rapidly. And the fungi number of fertilizer treatment was lower than the control group.Chaetomium globosum strain ND35 could control many plant diseases. Valsa sordida was served as an example, the influence of secondary metabolites of C. globosum ND35 on physiological and activities of key enzymes of metabolic pathway in the pathogen was investigated. The results showed that MDA content of treatment group was significantly higher than the control in the pathogen mycelium after treatment with the crude extracts from C. globosum ND35. The content of soluble protein was rapidly declining since the beginning of treatment, and was always lower than the control group. When the interaction time reached48 hours, the protein content in the treated group was only 59.1% of the control group, and the difference was significant. The conductivity values in the treated group increased rapidly,then post-stabilized, but significantly higher than the control. When the interaction time was24 hours, the conductivity difference was maximum between the two groups, and the treatment group higher than the control group above 49.1%. The activities of hexokinase(HK), pyruvate kinase(PK), lactate dehydrogenase(LDH) in glycolysis pathway and succinate dehydrogenase(SDH), malate dehydrogenase(MDH) in tricarboxylic acid cycle and the total ATP enzyme in energy metabolism were significantly decreased after treatment with the crude extracts, and were significantly lower than the control group. This showed thatthe metabolic pathway of pathogen was destructed. The pathogen could not carry out normal life activities. |
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