Control Effects And Mechanism Of Wuyiencin Against Sphaerotheca Macularis And Botrytis Cinerea

Wuyiencin is a novel agricultural antibiotic produced by Streptomyces ahygroscopicus var.wuyiensis. It has been widely used to control fungal pathogens of vegetable, fruit tree and crop. In orderto have a comprehensive understanding of control effects and mechanism of Wuyiencin, and to providea technical basis for the reasonable application of the agent, in this experiment the control effects of2%Wuyiencin AS against Sphaerotheca macularis and Botrytis cinerea were studied by bioassay and fieldtests. It effects on quality of strawberry and tomato fruit were estimated by determing the nutritionalcontent. The protective effect, curative effect and activity duration against Botrytis cinerea were studiedin pot tests. In addition, the changes of resistance-related enzymes in tomato plants treated byWuyiencin were detected. The main conclusions were as follows:1. Control effect of Wuyiencin against Sphaerotheca macularis. The indoor experiments showedthat Wuyiencin had a strong inhibition on the spore germination of Sphaerotheca macularis, withinhibition rates more than50%at the tested dosages. The field trial tests showed that the effects of66.67and50μg/mL Wuyiencin on strawberry powdery mildew were equal to the chemical fungicidedifenoconazole, while the effect of100μg/mL Wuyiencin was significantly higher than other treatments.Meanwhile, the agent was safe to the growth and development of strawberry without phytotoxicity.2. Control effect of Wuyiencin against Botrytis cinerea. Toxicity experiments showed thatWuyiencin could strongly inhibit the mycelium growth of Botrytis cinerea. The field trial tests showedthat100μg/mL Wuyiencin had an equal effect on tomato gray mould with the chemical fungicideprocymidone, while200μg/mL Wuyiencin had a significantly higher efficacy. Besides, Wuyiencin hadno side-effects on tomato growth and development at the tested dosages.3. Protective activity, curative activity and activity duration of Wuyiencin against Botrytis cinerea.Wuyiencin exhibited good protective effect and curative against tomato gray mould in pot test, and theprotective effect was prior to the therapeutic effect. At the same time, the duration was more than8daysagainst Botrytis cinerea.4. Effects of Wuyiencin on fruit quality. The detection of fruit quality showed that Wuyiencin couldincrease the contents of soluble solids and soluble sugar of strawberry fruit, and then the fruit sugar-acidratio was changed. The contents of soluble solids, vitaminC and soluble sugar of tomato fruit wereincreased except titratable acid. Test results indicated that Wuyiencin could improve the fruit quality tosome extent.5. Changes of main resistance-related enzymatic activities in tomato plants treated with Wuyiencin.The activities of SOD, POD, PPO and PAL were increased in the tomato plants treated with100μg/mLWuyiencin. When plants were inoculated by pathogen, the enzymatic activities were further stimulated,and were significantly higher than other treatments.