爵床提取物的抑菌杀虫活性研究

Fungicide and insecticide activity of Justicia procumbens extracts

爵床（Justiciaprocumbensvar．procumbensL．）是一种传统中药。为探明爵床提取物的抑菌杀虫活性，采用冷浸和超声波提取相结合的方法，分别获得了爵床甲醇、氯仿、丙酮、乙酸乙酯和正己烷等溶剂提取物；并应用抑菌圈法研究了5种提取物对柑橘炭疽病菌（Colletotrichumgloeosprioides）、芦笋茎枯病菌（Phomopsisasparagi）、稻瘟病菌（Pyriculariagrisea）、棉花红腐病菌（Fusariumgraminearum）和草莓灰霉病菌（Botrytiscinema）等5种植物病原真菌的抑制效果，测定了甲醇提取物对柑橘炭疽病、芦笋茎枯病、草莓灰霉病和柑橘溃疡病（Xanthomonascampestris）等4种植物病菌及白蚊伊蚊似edesalbopictus）、家蝇（Muscadomestica）和菜青虫（Pierisrapae）等3种害虫的毒力。结果表明，不同极性溶剂提取物8mg·mL-1对5种植物病原真菌均有一定的抑制作用，其中甲醇提取物对柑橘炭疽病菌、芦笋茎枯病菌、草莓灰霉病菌的抑制率均达50％以上。爵床甲醇提取物具有较强的抑菌杀虫活性，对柑橘炭疽病菌、芦笋茎枯病菌和草莓灰霉病菌菌丝生长的抑制中浓度（EC50）分别为5．94mg·mL-1、4．61mg·mL-1和5．27mg·mL-1，EC90分别为63．69mg·mL-1、58．01mg·mL-1和54．57mg·mL-1；0．25～1．00mg·mL-1爵床甲醇提取物对柑橘溃疡病病菌显示强抑菌作用，0．125mg·mL-1显示中度抑菌作用，最小抑制浓度（MC）为0．0625mg·mL-1；爵床甲醇提取物对白蚊伊蚊、家蝇和菜青虫的致死中浓度（LC50）分别为0．1958mg·mL-1、0．35l4mg·mL-1和0．2877mg·mL-1，LC95分别为0．9884mg·mL-1、3．0532mg·mL-1和2．5844mg·mL-1。因此，爵床提取物作为生物农药，在农业生产中具有较好的应用前景。

Justicia procumbens is traditional Chinese medicine herb. To confirm fungicidal and insecticidal activity of J. procumbens extracts, methanol, chloroform, acetone, ethyl acetate and hexane extracts were obtained from J. procumbens by the combined method of cold-soaking and ultrasonic extraction. Extract inhibitory effects were studied using the inhibition zone method involving five species of plant pathogenic fungus--Colletotrichum gloeosprioides, Phomopsis asparagi, Pyricularia grisea, Fusarium graminearum and Botrytis cinerea. Methanol extract toxicity against four species of plant pathogenic fungus and bacteria （C. gloeosprioides, P asparagi, B. cinerea and Xanthomonas campestris） and three species of insects （Aedes albopictus, Musca domestica and Pieris rapae） were also assayed. Results showed that 8 mg·mL-1 extracts of/. procumbens with different polar solvents had some inhibitory effects on five species of plant pathogenic fungus. The inhibition rates of methanol extract against C. gloeosprioides, P asparagi and B. cinerea were over 50%. Methanol extract from J. procumbens had better fungicidal and insecticidal activity. ECs0 of methanol extract against mycelium growth of C. gloeosprioides, P asparagi and B. cinerea were 5.94 mg·mL-1, 4.61 mg·mL-1 and 5.27 mg·mL-1, respectively. The corresponding EC90 were 63.69 mg·mL-1, 58.01 mg·mL-1 and 54.57 mg·mL-1, respectively. Methanol extract at 0.25～1.00 mg·mL-1 showed strong inhibitory activity against X. campestris. The resultantextract at 0.125 mg·mL-1 showed moderate inhibitory activity. Methanol extract MIC was 0.062 5 mg·mL-1. Methanol extract LC50 against A. albopictus, M. domestica and P. rapae were 0.195 8 mg·mL-1, 0.351 4 mg·mL-t and 0.287 7 mg·mL-1, respectively. The corresponding EC95 were 0.988 4 mg·mL-1, 3.053 2 mg·mL-1 and 2.584 4 mg·mL-1, respectively. This suggested that J. procumbens extracts had better application prospects as a biological pesticide in agricultural production.