植物乙醇提取物对椰心叶甲生物活性的影响

定了假药、菠萝蜜、含羞草、飞机草、白花篙、腰果等6种植物乙醇提取物对椰心叶甲各龄幼虫和成虫的拒食活性、发育历期和成虫寿命的影响,以及对实验种群增长的控制作用。结果表明,所试植物乙醇提取物中假药乙醇提取物对椰心叶甲的拒食活性最好,在0.01g血L浓度下,1~5龄幼虫及成虫的拒食率分别为91.52%、71.34%、60.98%、48.98%、43.75%和67.38%。植物乙醇提取物处理后,椰心叶甲发育历期延长。0.01g血L假药乙醇提取物处理后,椰心叶甲完成1代所需时间为73.58d,明显长于对照的43.34d;而同浓度腰果乙醇提取物处理,椰心叶甲完成1代所需时间为48.6d,与对照无明显差异。对实验种群的作用因子生命表分析,结果表明,各植物乙醇提取物主要影响了椰心叶甲生殖力下降、卵不孵化和广2龄幼虫死亡,导致种群增长趋势下降,其干扰作用指数分别为0.0108、0.0386、0.1764、0.2458、0.3437和0.5179。     

31种热带植物乙醇提取物对朱砂叶螨的生物活性研究

室内测定31种植物乙醇提取物对朱砂叶螨的触杀和驱避作用.结果表明,大山芝麻、蜂巢草、仔榄树和许树乙醇提取物对朱砂叶螨具有明显的触杀作用,24h后平均校正死亡率达80％以上,其中大山芝麻的触杀效果最好,高达96.35％;23种植物提取物对朱砂叶螨产卵驱避作用显著,平均驱避率达90％以上;牛筋果、云南野桐、多花瓜腹木、黄椿木姜、酒饼簕和毛瓣鸡血藤提取物对成螨驱避作用明显且较为稳定,48 h的平均驱避率达91％以上.     

印楝提取物对瓜叶螟幼虫拒食活性的测定

研究6种印楝种仁提取物（编号为A，B，C，D，E，F）对瓜叶螟（Diaphania indica)幼虫的拒食活性。室内试验结果表明；印楝的6种提取物稀释10倍时，对瓜叶螟幼虫具有较强的拒食活性。24h非选择性拒食率分别为D100.0%，B96.1%,A93.2%,E87.5%,C76.5%,F66.6%；在稀释100倍时，处理后24h，提取物D对瓜叶螟幼虫具有较好的拒食作用，拒食率为96.5%,C61.6%，其他4种拒食活性较差。     

蟛蜞菊抽提物对花生蚜忌避及毒杀作用

用不同浓度蟛蜞菊甲醇抽提物对花生蚜选择性和非选择性忌避作用进行测定,并采用喷雾法进行蟛蜞菊抽提物对花生蚜的毒杀试验。结果表明:在选择性忌避试验中,蟛蜞菊抽提物对花生蚜具明显的忌避作用,最高忌避率达90.1％,而在非选择性忌避试验中忌避作用中等;2.5 g/L浓度蟛蜞菊抽提物喷雾处理花生蚜,第5天死亡率达93.7％,第1,3,5天致死中质量浓度(LC50)分别为1.4,1.2,0.9 g/L。蟛蜞菊抽提物有开发利用的价值。     

假蒟提取物对皮氏叶螨的生物活性测定

通过索氏抽提和乙醇浸提法提取假蒟(Rper.saormentosum Roxb.)杀虫活性成分,即获得乙醇浸提物、乙醇索氏提取物和石油醚索氏提取物,研究其对皮氏叶螨(Tetranychus pieroei McGregor)各龄虫的触杀及对成螨驱避、产卵抑制等方面的生物活性.结果表明:乙醇浸提物和石油醚索氏提取物对皮氏叶螨卵的毒杀效果均较好,用20mg/g的浓度处理后,杀卵效果均在95%以上:对若螨的生物活性以乙醇索氏提取物最好,当浓度为15mg/g时,校正死亡率达95.19%,明显强于石油醚索氏提取物;乙醇浸提物、乙醇索氏提取物和石油醚索氏提取物对成螨的LC50分别为3.2141,6.093 1,3.518 8 mg/g,LC95分别为8.5750,18.700 7,9.311 4 mg/g;用质量分数0.4%乙醇浸提物和石油醚索氏提取液处理的皮氏叶螨成螨寿命明显短于乙醇索氏提取物和对照,产卵抑制指数以石油醚索氏提取物最高,为0.1465,乙醇索氏提取物最低,为0.0825;3种提取物对皮氏叶螨均有良好的驱避作用.     

印楝素对水稻二化螟的生物活性及控制作用

 系统地研究了印楝素对水稻二化螟的生物活性及作用方式。试验结果表明，印楝素乳油对二化螟有胃毒、拒食、忌避、内吸等多种作用方式。0.75和0.50 mg/L印楝素乳油处理茭白饲喂3龄幼虫，幼虫分别于3、6 d内全部死亡；0.375、0.300和0.250 mg/L印楝素乳油低剂量处理茭白饲喂3龄幼虫，幼虫拒食率分别达94.38%、88.74%、80.07%；成虫产卵量分别下降80.70%、62.05%、40.86%。6、3和2 mg/L印楝素乳油处理初孵蚁螟，24 h内死亡率达100%。印楝素乳油对成虫产卵有显著的忌避作用。稻田喷施0.3%印楝素乳油62.5和125 mL/667 m2防治二化螟，21 d保苗效果分别为88.14%和94.13%，防治效果分别为85.36%和90.76%。表明印楝素对二化螟有较高的生物活性和理想的控制效果。     

辣蓼粗提物对茶尺蠖的生物活性

辣蓼（Polygonum hydropiper L）粗提物对茶尺蠖3龄幼虫的室内生物活性测定结果表明,以95％的酒精为溶剂的辣蓼提取物效果最佳。在触杀试验中,95％酒精提取物处理后3d和7d的校正死亡率分别达到了44.22％和52.40％,乙酸乙酯提取物在3d和7d后校正死亡率也达到了29.25％和31.97％;非选择性拒食作用结果表明,95%的酒精提取物具有良好的拒食效果,12h和24h的拒食率分别达到了90.29％和84.15%。     

虫粪提取物对甜菜夜蛾成虫产卵和幼虫取食的影响

为了明确甜菜夜蛾(Spodoptera exigua Hübner)幼虫虫粪对其成虫产卵及幼虫取食的影响,采用非选择实验的方法,选用丙酮、甲醇和正己烷3种溶剂对甜菜夜蛾幼虫虫粪中的物质进行提取,然后分别测定3种溶剂幼虫粪便提取物对成虫产卵及幼虫取食的影响。结果表明:丙酮和甲醇幼虫粪便提取物对甜菜夜蛾成虫产卵量有显著的抑制作用,产卵忌避率分别为45.68%和33.21%;而正己烷提取物对成虫产卵的抑制作用不显著。3种溶剂粪便提取物对1龄和4龄幼虫的取食量(面积)均没有显著影响,但显著影响2龄和3龄幼虫的取食行为,其对幼虫的取食抑制率依次为丙酮甲醇正己烷;另外,3种溶剂粪便提取物对甜菜夜蛾幼虫的存活率无显著影响。可见,甜菜夜蛾幼虫粪便中存在对成虫产卵和幼虫取食具有抑制作用的活性物质。     

大叶桃花心木的花、叶抽提物对斜纹夜蛾的拒食活性

以大叶桃花心木的花和叶为材料,测试了其乙醇抽提物对重要多食性害虫斜纹夜蛾5龄幼虫的拒食活性。结果表明:试剂中大叶桃花心木的花与叶各自的抽提物质量分数5％时均有较强的拒食作用,非选择性拒食率分别高达96.33％和86.23％,选择性拒食率分别高达96.63％和91.98％;质量分数5％大叶桃花心木花、叶抽提物拒食率在48 h后均有所下降,但仍然保持较高的拒食率,其非选择性拒食率分别为87.3％和73.9％,选择性拒食率分别为95.46％和85.63％;连续以质量分数1％的花、叶抽提物浸叶饲喂时,试虫体重的增长明显低于对照试虫,处理后第5天,质量分数1％的花、叶抽提物处理试虫的平均体重分别为对照的49.32％和53.01％。研究结果表明,大叶桃花心木的花、叶的乙醇抽提物对斜纹夜蛾均具有良好的拒食活性,并且大叶桃花心木的花抽提物对斜纹夜蛾的拒食活性高于其叶的抽提物。      

14种植物精油对茶尺蠖行为的影响

为获得能够应用于茶园茶尺蠖Ectropis obliqua“推—拉”策略的行为调节剂,在室内测定了茶尺蠖成虫对14种植物精油的趋性反应,及植物精油对茶尺蠖雌虫产卵行为的干扰作用,并采用叶碟法测定了植物精油对茶尺蠖幼虫的拒食作用。结果表明,罗勒、迷迭香、肉桂、茴香及天竺葵5种植物精油对茶尺蠖成虫表现出一定的驱避活性,并且迷迭香油和天竺葵油还能显著干扰雌虫的产卵活动。在3个浓度处理下,茴香、罗勒和藿香植物精油对茶尺蠖3龄幼虫表现出显著的拒食活性。随着精油处理浓度的升高,茶尺蠖幼虫的拒食率升高,生长率随之下降。试验结果证明迷迭香、罗勒、茴香及天竺葵等植物精油对茶尺蠖具有显著的行为调控功能,具备作为茶尺蠖防控剂开发的潜力,值得进一步研究。     

几种植物乙醇提取物对螺旋粉虱的生物活性

采用玻管药膜法和田间试验研究飞机草、青葙、假蒟等6种植物叶片的乙醇提取物对螺旋粉虱的生物活性.结果表明,各供试提取物均对螺旋粉虱表现出一定的生物活性,其中以飞机草和青葙的活性最高,其LC50分别为753.40,999.81 mg/kg,其余4种提取物对螺旋粉虱的活性大小依次为:假茼>菠萝蜜>含羞草>桃金娘.田间试验结果表明,飞机草和青葙提取物对螺旋粉虱成虫均具有较高活性,在50倍浓度处理下,飞机草和青葙提取物的防效均在75%以上.     

Toxic effects of neem-based insecticides on Pieris brassicae (Linn.)

Four neem-based insecticides, Neemix^® (0.25% EC @ 20 mg azadirachtin/liter), Ecozin^® (3% EC @ 20 mg azadirachtin/liter), Agroneem^® (0.15% EC @ 4.8 mg azadirachtin/liter) and Neem oil (0.25% EC azadirachtin @ 20 mg azadirachtin/liter) and a non-commercial neem leaf powder, were evaluated for oviposition deterrence, antifeedant effect to larvae and toxicity to eggs and larvae of Pieris brassicae (Linn.) on cabbage leaves in the laboratory. The concentrations tested were with in the ranges of recommended field rates. Oviposition deterrence in no-choice, two-choice and six-choice assays, was observed for all the treatments. They exhibited significant (P < 0.01) oviposition deterrence on P. brassicae when compared with a non-treated control. Cabbage leaves treated with the neem-based insecticides were used as an egg-laying substrate. Numbers of eggs oviposited by P. brassicae adults on treated cabbage leaves were significantly lower then those treated with water, but no significant differences were detected among the neem insecticides. They also deterred feeding by Pieris larvae and exhibited significant antifeedant effects. Larvae of P. brassicae on treated leaves stopped feeding and dropped from the leaf, resulting in no or minimal damage. Direct contact with neem-based insecticides decreased the survival of eggs. Survival of larvae fed for 9 days on leaves treated with neem-based insecticides was reduced to 51%, 49%, 48%, 24% and 18% in the Neem oil, Neemix, Agroneem, Ecozin and neem leaf powder treatments, respectively. Therefore, it can be concluded from the present investigations that neem-based insecticides had oviposition deterrence, antifeedant and toxic effect to P. brassicae.     

刚果12号桉对4种豆科植物的化感作用

采用室内生物检测的方法研究了刚果12号桉叶片自然释放的挥发性物质、叶片水抽提物、叶片经水蒸气蒸馏所得的桉油、含挥发性水溶性物质的冷凝水和含水溶性非挥发性物质的渣汁3个组分以及桉树根际土壤水浸液对绿豆、大豆、柱花草与大翼豆4种受体植物的化感活性。结果表明：刚果12号桉叶片释放的挥发性物质对4种受体植物种子的萌发有强烈的抑制作用：桉叶水抽提物与根际土壤水浸液对绿豆、大豆、柱花草与大翼豆4种受体植物种子萌发与幼苗生长不但有一定抑制作用，而且土壤水浸液对绿豆、大豆和柱花草幼苗的根生长还有不同程度的促进作用，处理分别比对照高出13％、2％、23％。从桉油、冷凝水与渣汁3个组分的化感活性来看，渣汁的最强，桉油次之，冷凝水最低，即单位叶片中水溶性物质的化感活性比挥发性的高。这表明水溶性化感活性物质可能是刚果12号桉的主要化感作用物质。     

A Survey of Woody Tropical Species for Boron Retranslocation

Abstract

The mobility in phloem of boron (B) has been reported to vary among plant species. Boron is phloem immobile in many species and completely mobile in others. Recent reports regarding phloem B mobility or immobility only considered temperate plants, and there is no information on tropical species. Information of phloem B mobility is useful for improving the diagnosis of B deficiency and management of B status in crop production. This study aimed to survey tropical species for their B mobility. Leaf samples of 17 species, including cashew (Anacardium occidentale L.), mango (Mangifera indica L.), custard apple (Annona squamosa L.), papaya (Carica papaya L.), cassava (Manihot esculenta Crantz.), Indian walnut (Samanea samen (Jacq.) Marrill.), cork wood tree (Sesbania grandiflora (L.) Pers.), tamarind (Tamarindus indica L.), jackfruit (Artocarpus heterophyllus Lamk.), guava (Psidium guajava L.), star fruit (Averrhoa carambola L.), passion fruit (Passiflora edulis Sims.), coffee (Coffea arabica L.), lime (Citrus aurantifolia Swingle.), longan (Euphoria longana Lam.), lychee (Lychi chinensis Sonn.) and teak (Tectona grandis L.) were collected in the position of the youngest fully expanded leaf (YFEL), the middle leaf age of a branch (ML) and the oldest leaf (OL). Based on a premise that the nutrient concentration gradient between young and old leaves will be steeper in those species in which B is immobile, B concentration in the different leaf positions was examined in comparison with calcium (Ca is phloem immobile) and potassium (K is phloem mobile). Concentrations of K in all leaf types were not significantly different or decreased with leaf age, while Ca concentrations were always higher in the older leaves. Three species; tamarind, guava and teak, showed concentration gradients of B that were similar to K. The results suggested that B may be retranslocated from older to younger leaves of these species, hence indicating that B may be phloem mobile in these species. However, this hypothesis needs confirmation through studies examining retranslocation of B using ¹⁰B isotope or identification of B-complexing molecules in the phloem, e.g. sugar alcohols.     

中草药提取物对 2 种杧果采后病原菌的抑菌活性

测定 71 种中草药丙酮提取物对杧果炭疽病菌 (Colletotrichum gloeosporioides Penz.) 和杧果蒂腐病菌(Botryodiplodia theobromae Pat.)的抑菌活性以及对杧果（Mangifiera indica L.）采后炭疽病和蒂腐病的防治效果。试验结果表明,在 20 mg/mL 浓度下,丁香、肉桂、花椒、八角、肉豆蔻、山萘、益智、胡椒、荜茇等 9 种中草药提取物对该 2 株病原菌的平均抑制率大于 70 %,EC 50 的平均值为 4.30 mg/mL。在该浓度下,八角、荜茇提取物能有效降低杧果采后病害的发病率和发病指数,对杧果炭疽病的防效分别为 92.32 %、88.01 %,对杧果蒂腐病的防效分别为 55.07 %、56.79 %。     

41％草甘膦异丙胺盐水剂防除柑橘园杂草药效试验

对41％草甘膦异丙胺盐水剂防除柑橘园杂草进行田间药效试验。结果表明,安徽省国家农药剂型工程技术中心生产的41％草甘膦异丙胺盐水剂对桔园内狗牙根、小飞蓬、蛇莓等常见的单、双子叶杂草均有理想的防效,30天株防效99．35％,鲜重防效98．68％。安徽省国家农药剂型工程技术中心提供的41％草甘膦异丙胺盐水剂具有安全、高效、药效期长等优点,适合作为柑橘园杂草的防除药剂,推荐施药剂量（制剂量）为4．5732L/hm2。     

Efficacy of medicinal plant extracts against Formosan subterranean termite, Coptotermes formosanus

The Formosan subterranean termite, Coptotermes formosanus Shiraki, is among the most devastating termite pests. Natural products derived from plant extracts were tested in a discovery programme for effective, environment friendly termite control agents. Screening for anti-termitic activity of plant extracts with some known medicinal attributes could lead to the discovery of new agents for termite control. The aim of this study was to investigate the anti-termitic activity of crude leaf hexane, ethyl acetate, acetone and methanol extracts of Andrographis lineata Wallich ex Nees. (Acanthaceae), Andrographis paniculata (Burm.f.) Wall. ex Nees. (Acanthaceae), Argemone mexicana L. (Papaveraceae), Aristolochia bracteolata Lam. (Aristolochiaceae), Datura metel L. (Solanaceae), Eclipta prostrata L. (Asteraceae), Sesbania grandiflora (L.) Pers. (Fibaceae) and Tagetes erecta L. (Compositae) against C. formosanus. An impregnated filter paper no-choice bioassay method was followed. All the crude extracts showed anti-termitic activity in a dose-dependent manner and exhibited a significant activity after 24 h and 48 h of exposure; the highest termite mortality was found in leaf hexane extract of A. bracteolata, ethyl acetate extract of A. paniculata, D. metel, E. prostrata, methanol extract of A. lineata and D. metel after 24 h (LD₅₀ = 363, 371, 298, 292, 358 and 317 ppm; LD₉₀ = 1433, 1659, 1308, 1538, 1703 and 1469 ppm), respectively. The hexane extract of T. erecta, acetone extract of A. mexicana, methanol extract of S. grandiflora and T. erecta showed activity after 48 h (LD₅₀ = 245, 253, 289, 409 ppm; LD₉₀ = 1378, 1511, 1508 and 2425 ppm), respectively. Among the natural products tested, may provide a renewable source of safe natural wood preservatives. These findings corroborate traditional insecticidal application of selected plants and the results can be extended for the control of termites. The primary objective of the present study was to identify novel, natural chemotypes from biologically active crude plant extracts that may be useful as part of termite treatment regimens in their natural form or as synthons for structure-activity studies in the future. The results reported here open the possibility of further investigations of efficacy on their anti-termitic properties of natural product extracts.