Screening of natural drug molecules against Fusarium oxysporum of ginseng root rot based on machine learning / 药学学报

italic>Fusarium oxysporum widely exists in farmland soil and is one of the main pathogenic fungi of root rot, which seriously affects the growth and development of plants and often causes serious losses of cash crops. In order to screen out natural compounds that inhibit the activity of Fusarium oxysporum more economically and efficiently, random forest, support vector machine and artificial neural network based on machine learning algorithms were constructed using the information of known inhibitory compounds in ChEMBL database in this study. And the antibacterial activity of the screened drugs was verified thereafter. The results showed that the prediction accuracy of the three models reached 77.58%, 83.03% and 81.21%, respectively. Based on the inhibition experiment, the best inhibition effect (MIC = 0.312 5 mg·mL-1) of ononin was verified. The virtual screening method proposed in this study provides ideas for the development and creation of new pesticides derived from natural products, and the screened ononin is expected to be a potential lead compound for the development of novel inhibitors of Fusarium oxysporum.

Optimal Potassium Application Rate for Panax ginseng / 中国实验方剂学杂志

ObjectiveThe law of fertilizer requirement serves as the basis for the fertilization of medicinal plants， development of special fertilizer， and high-quality medicinal materials. MethodThis study aims to explore the optimal potassium application rate for Panax ginseng to achieve high yield and quality of the medicinal material and targeted management of potassium fertilizer. To be specific， 6 concentration gradients （0， 2， 4， 8， 10， and 12 mmol·L-1） of potassium sulfate （potassium fertilizer） were designed and applied to the 4-year-old P. ginseng in CK， C1， C2， C3， C4， and C5 treatments， respectively. Thereby， the influence of potassium concentration on P. ginseng was observed. ResultWhen potassium sulfate was applied at 8 mmol·L-1， P. ginseng had the chlorophyll content of 32.13%， net photosynthetic rate of 2.548 8 µmol·m-2·s-1， and activities of superoxide dismutase （SOD）， peroxidase （POD）， and catalase （CAT） significantly higher than those in the CK， C1， C4， and C5 treatments （P<0.05）. The average fresh weight of P. ginseng roots was 6.25 g， 134% up from the CK， and the content of ginsenoside Rg1 （5.24 mg·g-1） and Re （4.17 mg·g-1） and total saponins （12.33 mg·g-1） was significantly higher than that in CK and other treatments （P<0.05）. Thus， 8 mmol·L-1 potassium sulfate was most favorable for the growth and effective component accumulation of four-year-old P. ginseng. ConclusionThis study expounds the effect of potassium fertilizer on the yield and quality of P. ginseng， which is expected to help guide the precise application of potassium fertilizer in P. ginseng production in the field and lay a theoretical basis for the development of special fertilizer for P. ginseng and the optimization of fertilization technology.