| Rehmannia glutinosa Libosch is a perennial herb of Scrophulariaceae, and is one of the earliest medicinal plants that have been cultivated in China. Its root is used frequently as a crude drug in traditional Chinese medicine. However,after continuous cropping the Rehmannia glutinosa Libosch will have serious disease ,Yield lower and cannot be planted again about 8~10 years at the same place. Also, physical control and chemical control are usually taken to control these diseases. The methods have Anti-bad effect and will cause pesticide residues. Therefore, at the basis of laboratory results, the paper uses 10 kinds of beneficial bacteria that laboratory obtained to do plate antagonistic experiment and field plot experiment.And then measured the effects of growth of rehmannia glutinosa under field conditions, explored the culture conditions and preservation conditions of the 10 kinds of beneficial bacteria. At the same time, 47 kinds of fungi were isolated from the rhizosphere soil of Rehmannia glutinosa Libosch and used them to do pot experiment and tissue culture seedling.Four kinds of pathogenic fungi were determined and then four kinds of beneficial fungi which have a good antagonistic effect for pathogenic fungi were determined by pot experiment and plate antagonistic experiment. Finally, the antagonistic mechanisms of four kinds of beneficial fungi were explored and the beneficial fungi were primary identified. The main findings are as follows:1. The field plot experiment show that diseased plant rate under beneficial bacteria treatment have significant difference compared with the control. The control effect of B6,B7,B29 are best among them, the control effect can respectively reach 72.73%and 78.79%, the control effect of B24,B28,B45 also can reach more than50.00%, B23 and B34 have the worst control effect and reach 24.24% and 18.19%.The average plant height of Rehmannia glutinosa Libosch under beneficial bacteria treatment has no significant difference compared with the control, but the root tuber fresh weight have different difference. The yield-increasing effect of B29 is the most obvious and the increasing rate can reach 44.46%; secondly for B7and B6, which can respectively reach 33.06% and 31.08%; in addition, B24 and B28 can reach more than 15%.Although B21and B45 also have certain yield increasing effect,they have no significant compared with the control; B23,B34,B43 have worse yield increasing effect, their increasing rate are all less than 5%.The worst is B34, its increasing rate only reach 1.09%.2.By explored the culture conditions and preservation conditions of the 10 kinds of beneficial bacteria, we can find different beneficial bacteria can growth well under25~35℃,pH 4~9, Light conditions, shaking conditions.The 10 kinds of beneficial bacteria can adapt different medium.Using river sand is simple and easy to maintain bacterial activity very well.3. Using soil dilution planting isolate 47 kinds of fungi from rhizosphere soil of Rehmannia glutinosa Libosch, and used them to do pot experiment and tissue culture seedling. Four kinds of pathogenic fungi were determined. They are No.4, No.30, No.31 and No.42.4.The plate antagonistic experiment showed that the R-value of No.17 is at the scope of 0.21～0.59, the R-value of No.27 is at the scope of 0.26～0.7, the R-value of No.35 is at the scope of 0.3～0.71 and the R-value of No.45 is also at the scope of0.21～0.59.The pot experiment showed that the control effect of No.27 and No.45 anti- No.4 is the same as 50% carbendazol wettable powder, can reach 88.9%; the control effect of No.17 and No.27 anti- No.31 is also similar to 50% carbendazol wettable powder, can reach 66.7%; the control effect of No.45 anti- No.31 is better than 50% carbendazol wettable powder, can reach 88.9%; the control effect of No.27 anti- No.42 is also as the same as 50% carbendazol wettable powder, can reach 88.9%.By continuous observed the growth of four kinds of beneficial fungi under microscope find that No.17 is T. aureoviride,No.27 is T. viride,No.35 is T .pseudokoningii and No.45 is T. harzianum.5.By study the antagonistic mechanism of antagonistic microorganisms find that B6,B7,B21,B28,B29,B45 main by antibiotic action against the pathogens; T17,T27,T35,T45 main by nutrient competition and spatial competition against the pathogens.In conclusion, B6,B7,B29 have Obvious yield-increasing effect for Rehmannia glutinosa Libosch and T17,T27,T35,T45 have good control effect to against the pathogens. They against the pathogens main by antibiotic action,nutrient competition and spatial competition.
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