[Objective] The research aimed to study antifeedant activity of Phytolacca acinosa Roxb., Setaria viridis （L.） Beauv and Viola yedoensis Makino extracts against Pieris rapae. [Method] Activity material was extracted...[Objective] The research aimed to study antifeedant activity of Phytolacca acinosa Roxb., Setaria viridis （L.） Beauv and Viola yedoensis Makino extracts against Pieris rapae. [Method] Activity material was extracted from S. viridis （L.）, P. acinosa and V. yedoensis using acetone cold soak method, and non-selective antifeedant activity of extracts to Pieris rapae larva was determined by using lobular plate addition method. [Result] The results showed that the acetone leaching agent of P. acinosa had most obvious antifeedant effects on Pieris rapae. The antifeedant rate were 74.53% and 82.34% at 24 and 48 h respectively. With the concentration increasing, the antifeedant effect of P. acinosa extracts increased. The antifeedant rate of 0.050 g/ml treatment was the highest, being 74.53% and 82.34% at 24 and 48 h. [Conclusion] P. acinosa could be studied and utilized as potential botanical insecticide.展开更多
Polyphenol oxidase （PPO） is the enzyme responsible for enzymatic browning during the growth of insects. It is also involved in defense reactions and is related with immunities in insects. PPO a metalloenzyme oxidase...Polyphenol oxidase （PPO） is the enzyme responsible for enzymatic browning during the growth of insects. It is also involved in defense reactions and is related with immunities in insects. PPO a metalloenzyme oxidase, catalyzes the oxidation of o-diphenol to o-quinone. The present paper describes the effects of benzaldehyde and its p-substituted derivatives on the activity of PPO from the fifth instar of Pieris rapae L. PPO from the fifth instar of Pieris rapae L. was purified using ammonium sulfate fractionation and chromatography on Sephadex G-100. The enzyme kinetics was characterized using L-3,4-dihydroxyphenylalanine （L-DOPA） as substrate. The results show that benzaldehyde, phydroxybenzaldehyde, p-chlorobenzaldehyde, and p-cyanobenzaldehyde can inhibit the PPO activity for the oxidation of L-DOPA. The inhibitor concentration leading to 50% activity lost, IC50, was estimated to be 5.90, 5.62, 2.83, and 2.91 mmol/L for the four tested inhibitors, respectively. Kinetic analyses show that the inhibitory effects of these compounds are reversible. Benzaldehyde, phydroxybenzaldehyde, and p-chlorobenzaldehyde are noncompetitive inhibitors while p-cyanobenzaldehyde is a mixed-type inhibitor. The inhibition constants were determined for all four inhibitors. p-chlorobenzaldehyde and p-cyanobenzaldehyde were more potent inhibitors than the other compounds. These results provide a basis for developing PPO inhibition-based pesticides.展开更多
文摘[Objective] The research aimed to study antifeedant activity of Phytolacca acinosa Roxb., Setaria viridis （L.） Beauv and Viola yedoensis Makino extracts against Pieris rapae. [Method] Activity material was extracted from S. viridis （L.）, P. acinosa and V. yedoensis using acetone cold soak method, and non-selective antifeedant activity of extracts to Pieris rapae larva was determined by using lobular plate addition method. [Result] The results showed that the acetone leaching agent of P. acinosa had most obvious antifeedant effects on Pieris rapae. The antifeedant rate were 74.53% and 82.34% at 24 and 48 h respectively. With the concentration increasing, the antifeedant effect of P. acinosa extracts increased. The antifeedant rate of 0.050 g/ml treatment was the highest, being 74.53% and 82.34% at 24 and 48 h. [Conclusion] P. acinosa could be studied and utilized as potential botanical insecticide.
基金Supported by the Science and Technology Foundation of Fujian Province (No. 2004N002)the National Natural Science Foundation of China (No. 30570408)
文摘Polyphenol oxidase （PPO） is the enzyme responsible for enzymatic browning during the growth of insects. It is also involved in defense reactions and is related with immunities in insects. PPO a metalloenzyme oxidase, catalyzes the oxidation of o-diphenol to o-quinone. The present paper describes the effects of benzaldehyde and its p-substituted derivatives on the activity of PPO from the fifth instar of Pieris rapae L. PPO from the fifth instar of Pieris rapae L. was purified using ammonium sulfate fractionation and chromatography on Sephadex G-100. The enzyme kinetics was characterized using L-3,4-dihydroxyphenylalanine （L-DOPA） as substrate. The results show that benzaldehyde, phydroxybenzaldehyde, p-chlorobenzaldehyde, and p-cyanobenzaldehyde can inhibit the PPO activity for the oxidation of L-DOPA. The inhibitor concentration leading to 50% activity lost, IC50, was estimated to be 5.90, 5.62, 2.83, and 2.91 mmol/L for the four tested inhibitors, respectively. Kinetic analyses show that the inhibitory effects of these compounds are reversible. Benzaldehyde, phydroxybenzaldehyde, and p-chlorobenzaldehyde are noncompetitive inhibitors while p-cyanobenzaldehyde is a mixed-type inhibitor. The inhibition constants were determined for all four inhibitors. p-chlorobenzaldehyde and p-cyanobenzaldehyde were more potent inhibitors than the other compounds. These results provide a basis for developing PPO inhibition-based pesticides.
文摘在温度为20～22℃的实验室条件下,用AfMNPV和PrGV的混合病毒悬液感染3龄期菜粉蝶幼虫,可有效降低2种病毒的用量,并显示出良好的增效作用,PrGV和AfMNPV毒力倍数分别为单剂的600倍和400倍以上.不同浓度混合病毒悬液的LT50分别比AfMNPV和PrGV单剂的LT50缩短1.10～2.06 d和0.40～1.93 d.用PrGV病毒悬液感染4龄期菜粉蝶幼虫,其LT50比3龄期增加3.43～6.06 d.
