| Pepper (Chili pepper) as a popular vegetable belongs to Capsicum Linn, Solanaceae, cultivated widely in the country, and use in medicinal. In2010, the pepper Sclerotinia was first discovered in Shuangliu county, Sichuan province, resulted the pepper death, the incidence rate is over30%and the yield was greatly reduced. In the previous reports of studies on Brassica campestris L. of Cruciferae, Glycine max of Leguminosae sp., Helianthus annuus of Asteraceae are much more, but the pepper Sclerotinia is very rarely reported. The paper is studied on symptoms of disease, culture characteristics of pathogen, morphological features, biological characteristics, ITS, laboratory fungicide screening and control effect in the field.The whole growth period of pepper may be subject to the hazards of Sclerotinia. From the pepper flowering period to the fruiting period, the disease occurs and causes the whole plant die. The mycelium like white floccules began to appear after incubation of three days and assembled into a group. Mycelium group from brown turn to black in the incubation during4-7days. The sclerotias have rough surface, hard, circular or irregular-shaped, and white or slightly pink inside. Mycelium grew on PDA medium and resulted in a few pigment (gray). The sclerotias germinate and form apothecium like as the cup form, light flesh-colored to brown. Asci are cylindrical, containing8ascospores, Paraphyses is slender and linear.In according with the determination method of Koch’s rules, the isolates were tied back to the plant health, after10days, inoculation symptoms consistent with field symptoms. Iinoculation fit with initial bacterial strain. Though ITS-DNA sequence analysis, Pepper Sclerotinia sclerotiorum and JN013184.1of five kinds in GenBank have highly homologue, and studied symptoms of disease, the morphological features and culture characteristics of pathogen, Results showed that the pathogen which is isolated and identified from infected pepper was Sclerotinia scleroriorumThe biological characteristics of sclerotinia sclerotiorum are studied in the paper. The results showed that the temperature range for mycelium growth was10℃～30℃, the optimum was20℃～25℃. The mycelium might grew from pH3to pH11, the favorable was pH5-pH7. Mycelium growth worst in sodium nitrate, the best are alanine and peptone. The sucrose was more favorable for mycelial growth than fructose. Mycelium lethal temperature was55℃for10min. The sclerotia could germinate at the treatments from10℃to30℃. The sclerotia grew well at medium except rice bran medium. The sclerotia might germinate from pH3to pH11and the best at pH3-pH7. The fructose is not beneficial for the sclerotia germination, the peptone was more favorable for sclerotia germination than others. The sclerotia lethal temperature was70℃for10min. The sclerotia could not germinate more than45days. Through the study on biological characteristics of sclerotinia sclerotiorum, in order to control pepper of Sclerotinia sclerotiorum, providing theoretical basis.For seven kinds of pharmaceutical, the best inhibiting effect to mycelia growth were50%procymidone WP and43%tebuconazole SC. The effects are100%. the best inhibiting effect to mycelia growth were70%thiophanate-methyl WP, The effects are58.8%～89.4%.50%carbendazim WP and10%antimycin WP are no inhibiting effect at the low concentrations, but in the high concentrations, the effects are71.8%～84.7%.In all concentrations, the no inhibiting effects are50%iprodione WP and58%pepper Junke WP. The best inhibitory effect was86.21%with43%tebuconazole SC, the second was79.31%with50%procymidone WP, the worst was70.11%with70%methyl thiophanate WP. |
PDF Full Text Request