白喉乌头总生物碱抑菌杀虫活性的初步研究

以平皿法和凹玻片法测定白喉乌头总生物碱提取物对稻瘟病菌、意大利青霉、甜瓜枯萎病菌、瓜类腐皮镰孢菌、黄瓜疫霉病菌5种植物病原菌的抑制作用;测定提取物对棉蚜的触杀活性、拒食活性和内吸活性.初步研究表明,白喉乌头总生物碱对5种植物病原菌的菌丝生长均有明显的抑制作用;对甜瓜枯萎病菌、瓜类腐皮镰孢菌、黄瓜疫霉病菌的孢子萌发也有较好的抑制作用,但对稻瘟病菌和意大利青霉无抑制作用.对棉蚜的触杀活性测定表明药后24、48和72 h LC50分别为14.30、9.30和7.84 mg/mL;100 mg/mL浓度下药后24和48 h拒食率分别为87.63;和93.81;;同时未观察到有内吸活性.

Primary Studies on the Fungicidal and Insecticidal Activities of Total Alkaloids from Aconitum leucostomum Worosch

Inhibitive effect of alkaloids from A.leucostomum on Magnaporthe grisea,Penicillium italicum Wehmer,Fusarium oxysporum f.sp melonis,Fusarium solani(Mart.) App.et Wollenw and Phytophthora drechsleri were investigated by petri plate test and concave slides test.And bioactivity of the extracts against Aphis gossypii Glover including contact toxicity,antifeeding toxicity and systemic toxicity were approached.Primary research showed that alkaloids from A.leucostomum had obviously inhibitory effect on the mycelial growth of all the five pathogens,and had obviously inhibitory effect on the spore germinations of F.oxysporum,F.solani and P.drechsleri;The LC50 of the contact toxicity against A.gossypii were 14.30 mg/mL,9.30 mg/mL,7.84 mg/mL after 24 h,48 h and 72 h respectively.Under the concentration of 100 mg/mL,the antifeeding rate reached 87.63% and 93.81% after 24 and 48 h respectively.And no systemic toxicity was observed.