| Ginseng is a herbaceous plant of the genus Araliaceae.Continuous cropping obstacle has been one of the important reasons for limiting the development of ginseng industry in the history of cultivated ginseng,and the causes of continuous cropping obstacle are complicated.Therefore,this paper mainly studied the chemotactic effects of ginseng saponins on ginseng root pathogens,and provided a theoretical basis for solving the cultivation of ginseng continuous cropping obstacle and ginseng.The research results were as follows:1)The chemotactic reactions of Fusarium solani,Cylindrocarpon destructans on panaxadiol aglycon,protopanaxadiol aglycon,Re and Rd were explored.The optimal chemotactic conditions for panaxadiol aglycon and protopanaxadiol aglycon for Cylindrocarpon destructans and Fusarium solani were chemotactic concentration of 5 mg/L,chemotactic pH of 7,chemotactic temperature of 25 ?,chemotactic time of 4 days.The optimal chemotactic conditions for Re for Cylindrocarpon destructans were chemotactic concentration of 50 mg/L,chemotactic pH of 6,chemotactic temperature of 25 ?,and chemotactic time of 4 days.The optimal chemotactic conditions for Re for Fusarium solani were chemotactic concentration of 0.5 mg/L,chemotactic pH of 7,chemotactic temperature of 25 ?,and chemotactic time of 4 days.The optimal chemotactic conditions for Rd for Fusarium solani and Cylindrocarpon destructans were chemotactic concentration of 5 mg/L,chemotactic pH of 8,chemotactic temperature of 25 ?,and chemotactic time of 4 days.At the optimal chemotactic concentration,chemotactic temperature and chemotactic pH,the spore germination rates of panaxadiol aglycon,protopanaxadiol aglycon,Re and Rd to Cylindrocarpon destructans were 80.33 %,81.67 %,76.67 % and 70.33 %;The optimal CMI were 1.1300,1.1300,1.0568,1.0466;The dry weight of mycelium were 0.3722,0.3967,0.2867,0.2833mg/mL.The spore germination rates of Fusarium solani were 80.00 %,74.33 %,75.33 % and 78.00 %;The best CMI were 1.1533,1.2000,1.0690 and 1.0994;The dry weight of myceliumare were 0.3133,0.3344,0.2558 and 0.2633 mg/mL.2)The effects of ginsenoside saponins,panaxadiol aglycon,protopanaxadiol aglycon,Rd and Re on Erwinia carotovora chemotaxis were studied.At the chemotactic concentration of 5 mg/L,ginsenoside saponins,panaxadiol aglycon and protopanaxadiol aglycon had the strongest chemotactic effect on Erwinia carotovora;However the chemotactic concentration was 0.5 mg,Rd and Re had the strongest chemotactic effect on Erwinia carotovora;At the chemotactic pH of 7,panaxadiol aglycon,protopanaxadiol aglycon and Re had the strongest chemotactic effect on Erwinia carotovora;At the chemotactic pH of 8,the chemotaxis of ginsenoside saponins and Rd were the strongest;In the range of chemotactic temperature and chemotactic time,30 ? and 60 min were the optimal chemotactic temperature and optimal chemotactic time of these five kinds of chemotactic liquids against Erwinia carotovora.3)The enzyme activity of PG,PMG,CX,PGTE and PMTE were extracted and the activity was determined by artificial culture of Erwinia carotovora.The results showed that five cell wall degrading enzymes were produced during the process of Erwinia carotovora infecting ginseng,and the activity of cell wall degrading enzyme produced by artificial culture Erwinia carotovora were different.It was speculated that it was possible that the chemotactic solution affected the degrading enzymes activity of cell wall.4)Studies had shown that in the CK group,Erwinia carotovora had only a slight cavitation phenomenon,and its reproductive state was observed in the electron micrograph,while both group A and B had heavier cavitation,and no reproductive state was observed in the electron micrograph.The group B had unexplained material spillage,and the bacterial cells become slender,therefore,it was concluded that higher concentrations of aglycone and ginsenoside had adverse effects on Erwinia carotovora,and the adverse effect of Aglycone on Erwinia carotovora was greater than ginsenoside.5)GC-TOF-MS was determined for Erwinia carotovora and Erwinia carotovora culture media treated with different chemotactic solution.In the examination of Erwinia carotovora,a total of 981 peaks were detected,on the premise of clarify its substance and qualitative reliability(Similarity >700),and there were 1 substances not contained in Group B,4 substances were not contained in the CK group;In the measurement results of the Erwinia carotovora culture solution measured by GC-TOF-MS,a total of 492 peaks were detected,on the premise of clarify its substance and qualitative reliability(Similarity >700),and one of the substances were not contained in the CK group. |
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