鱼藤属植物内生真菌的分离及杀虫活性研究

本文是以毛鱼藤、白花鱼藤、蜜花鱼藤3种鱼藤属植物为试验材料,分离筛选代谢物具有生物活性的内生真菌菌株。通过组织分离法,从3种鱼藤属植物中分离得到4株代谢表现旺盛的内生真菌菌株。杀虫活性实验表明:4种内生真菌的代谢产物对松材线虫都具有一定的毒杀作用,其中青霉菌的代谢产物活性最高,48 h校正死亡率达90%以上。4种内生真菌中,只有青霉菌的代谢产物对家蚕4龄幼虫具有触杀活性,1.5 mg/头剂量处理时,24 h校正死亡率即达到100%。     

鄂尔多斯半日花提取物的杀线虫作用

为全面了解濒危植物半日花的价值,测定并比较半日花不同浓度的6种提取物药液对松材线虫的生物活性,选出有较强杀线虫活性的甲醇、乙醇及水提取物,系统研究了提取物种类、浓度和处理时间对松材线虫死亡率的影响。三因素方差分析表明,提取物种类(A)、处理浓度(B)和处理时间(C),三因素的互作效应(A×B×C)和双因素互作效应(A×B、A×C、B×C)对线虫的校正死亡率都有极显著影响。最佳药液处理为:水提取物在6mg.L-1浓度时与1d的作用组合和乙醇提取物在3mg.L-1浓度时与5d的组合,以上两种组合的校正死亡率均达到100%。比较水、乙醇提取物5d中的LC50值,确定水是提取活性物质的首选溶剂。     

巴豆提取物对玉米象的生物活性

研究了巴豆(Croton tigliumL.)4种溶剂提取物对玉米象Sitophilus zeamais(Motschulsky)成虫的驱避作用和触杀作用。结果表明:巴豆的4种溶剂提取物对玉米象Sitophilus zeamais(Mostchulsky)成虫均有很好的触杀作用,7.86 mg/cm2的浓度处理后,4 d后的校正死亡率均达到100%。巴豆的4种溶剂提取物对玉米象成虫没有明显的驱避作用。     

夹竹桃叶乙醇提取物对斑马鱼的毒性评价

研究表明, 夹竹桃(Nerium indicum Mill.)及其提取物对多种害虫具有较强的毒杀作用, 已在害虫生物防治中显示出较大作用。为了合理开发夹竹桃植物, 需要进一步评价夹竹桃植物对水生生物的安全性和对动物的毒理学。文章利用索氏提取法提取夹竹桃叶乙醇粗提物, 并进一步用氯仿萃取浓缩、硅胶柱层析方法提取分离乙醇精提物, 经鉴定为强心甙组分。在此基础上, 委托浙江省医学科学院评价了乙醇粗提物对实验动物的毒理学, 并采用静态法评价了这二种提取物对斑马鱼(Brachydanio rerio)的急性毒性和慢性效应。结果表明: 夹竹桃叶乙醇粗提物的提取率为45%, 乙醇精提物(主要成分为强心甙组分)的提取率为0.25%。乙醇粗取物对大鼠经口和经皮毒性为低毒级, 对家兔皮肤和眼无刺激, 对豚鼠的致敏反应属弱致敏性。这说明夹竹桃叶乙醇粗提物对哺乳动物十分安全。在急性毒性试验中, 发现斑马鱼的死亡率与提取物处理浓度和处理时间均呈明显的正相关。处理浓度越大, 斑马鱼的死亡率越高; 同一浓度处理时间越长, 死亡率越高。用24 mg/L 乙醇粗提物处理6、12、24 和48h 的死亡率分别为26.67%、60%、91.11%和95.56%; 用0.5 mg/L乙醇精提物处理12、24、48、72 和96h 的死亡率分别为6.25%、33.33%、52.08%、54.17%和60.42%; 用24 mg/L 乙醇粗提物处理96h 或32 mg/L 处理48h, 或者用1 mg/L 乙醇精提物处理24h, 斑马鱼全部死亡。在慢性毒性试验中, 用3.33-10.0 mg/L 乙醇粗提物处理斑马鱼28d, 其死亡率为12%-20%。乙醇粗提物处理斑马鱼后, 急性毒性LC50=12.52 mg/L(药后96h)10 mg/L, 慢性毒性LC50=199.51 mg/L(药后28d); 乙醇精提物处理斑马鱼后, 急性毒性LC50=0.46 mg/L(药后96h)1 mg/L, 根据《化学农药环境安全评价试验准则》(1990)中农药对鱼类的毒性分级标准, 说明夹竹桃叶乙醇粗提物对斑马鱼的毒性属于低毒, 比较安全; 乙醇精提物对斑马鱼的毒性则为高毒, 十分不安全。       

植食性昆虫的组成和波动对红树林群落演替的影响

为了解红树植物植食性昆虫在不同季节、不同潮位和不同寄主植物上的种类、密度差异和主要特点及其对红树植物树冠层所造成的影响,进而分析植食性昆虫对红树植物群落演替的影响,在山口红树林保护区设置5个断面,分别于雨季(7月)和旱季(2月),在每个断面的高潮位(H)、中潮位(M)和低潮位(L)针对不同植物抽样,统计叶片被食率,记录植食性昆虫的种类和密度。植食性昆虫共有23种,其中鳞翅目有13种,半翅目8种,鞘翅目1种,直翅目1种,真螨目1种。主要昆虫种类有海榄雌瘤斑螟(Ptyomaxia sp.)、毛颚小卷蛾(Lasiognatha cellifera)、白囊袋蛾(Chalioides kondonis)、广翅蜡蝉(Ricania sp.)、潜叶蛾(Phyllocnistis sp.)和蛎盾蚧(Lepidosaphes sp.)。雨季和旱季的密度均为广翅蜡蝉较高(7.31头·枝-1);不同断面红树植物叶片被食率旱季为C5C2≥C3≥C1,雨季为C5C2≥C3≥C1C4;不同潮位的叶片被食率旱季为中潮位≥高潮位低潮位,雨季为中潮位低潮位≥高潮位;不同树种的叶片被食率旱季为秋茄≥桐花树≥红海榄≥白骨壤,雨季为秋茄桐花树白骨壤≥红海榄≥木榄≥无瓣海桑≥海漆。红树植物叶片上的昆虫多为小型个体,植食性为主,多具有卷叶习性和粘附特征;蚂蚁、寄生蜂和捕食性蜘蛛等天敌类昆虫种类较少,昆虫密度一旦增加,较大可能会变成害虫,从而对树冠层的稳定造成较大的影响。植食性昆虫可在一定程度上推动红树林群落的演替。     

40种杂草的丙酮提取物对3种植物病原真菌的抑菌活性

在离体条件下研究了40种杂草的丙酮提取物对辣椒疫霉(Phytophthora capsici Leonian)、尖孢镰刀菌(Fusarium oxysporium Schl.)和灰葡萄孢(Botrytis cinerea Pets.)3种植物病原真菌的抑菌活性.结果表明,有7种杂草的丙酮提取物至少对1种供试病原菌的抑制率在60%以上.其中,黄花蒿(Artemisia annua L.)、苍耳(Xanthiumsibiricum Patrin)和荔枝草(Salvia plebeia R. Br.)的丙酮提取物对3种病原菌的抑制率都在60%以上;鳢肠(Ecliptaprostrata L.)的丙酮提取物对辣椒疫霉和尖孢镰刀霉的抑制率在60%以上;车前(Plantago asiatica L.)、夏至草[Lagopsis supina(Steph.)IK.-Gal.]和泽漆(Euphorbia helioscopia L.)的丙酮提取物对灰葡萄孢的抑菌效果较好.     

《中国动物志》(昆虫纲 鳞翅目 舟蛾科)

舟蛾科 (中名旧称天社蛾科 )是鳞翅目夜蛾总科中一个中等大小的科 ,全世界已记载约 3 5 0 0种。舟蛾大都是林木害虫 ,在森林、防护林、行道树、果树和苗圃等场所常有发生 ,也有少数种类为害禾本科农作物 ,个别种类 (如杨二尾舟蛾 )甚至可咬破电缆 ,造成电路事故。杨扇舟蛾、杨小舟蛾和杨二尾舟蛾是重要的杨、柳树害虫。1 979年出版的《中国经济昆虫志》(鳞翅目　舟蛾科 )记述了我国舟蛾 1 70种。随着我国舟蛾科昆虫已知种类的大量增加及舟蛾系统分类研究的进展和不断变动 ,《中国经济昆虫志》(舟蛾科 )的内容已远远不能满足科研、教学和生产…     

菊苣叶片不同溶剂提取物对粘虫的生物活性

采用冷浸和超声波提取相结合的方法,分别获得了菊苣(Cichorium intybus L.)叶片乙酸乙酯、乙醚和石油醚提取物;并应用饲喂称重法及叶碟法研究了这3种提取物对粘虫(Mythimna separata Walker)幼虫生长发育的影响及拒食效应.结果表明:菊苣叶片乙酸乙酯提取物的得率显著高于乙醚和石油醚提取物,3种提取物的得率分别为4.36%、1.96%和1.08%.在实验期内(9 d),3种提取物处理组的试虫个体质量均显著低于对照组(P＜0.05),且各处理组间总体上差异显著;其中,乙酸乙酯提取物处理组试虫的个体质量最小,发育抑制率最高并随培养时间延长持续增高,饲养第9天发育抑制率达到79.27%;乙醚和石油醚提取物处理组的发育抑制率则表现为先升高后降低的趋势,均在饲养第5天达到最高,分别为62.44%和45.83%.各处理组试虫的死亡率和单蛹质量均显著高于对照组,化蛹率(50.00%～80.00%)均显著低于对照组.其中,乙酸乙酯提取物处理组试虫的死亡率和校正死亡率均最高,分别为57.80%和52.05%.各处理组试虫的幼虫期与对照组也有显著差异,分别较对照组延长了3.62～11.78 d.各处理组对试虫的拒食作用显著高于对照组,其中,乙酸乙酯提取物处理组的拒食率最高;乙酸乙酯、乙醚和石油醚提取物处理组72 h的拒食率分别为84.43%、76.46%和16.67%.研究结果显示,菊苣叶片的乙酸乙酯、乙醚和石油醚提取物对粘虫均有致死及抑制生长发育的作用,尤其是乙酸乙酯提取物的生物活性更强,可作为天然植物源驱虫剂进行开发利用.     

亮叶中南鱼藤的杀虫活性及有效成分

研究了亮叶中南鱼藤Derris fordii var. lucida的杀虫活性及有效成分。通过生物测定确定了该植物提取物对几种害虫的杀虫活性及其作用方式,并在活性跟踪的基础上,通过萃取、柱层析、薄层制备、重结晶、核磁共振和质谱等方法对其有效成分进行了分离和鉴定。结果表明,亮叶中南鱼藤不同部位甲醇提取物中仅根部提取物表现出杀虫活性。根甲醇提取物对白纹伊蚊Aedes albopictus 4龄幼虫、棉蚜Aphis gossypii Glover 无翅成蚜、豆蚜Aphis craccivora Koch无翅成蚜、桃蚜Myzus persicae (Sulzer)无翅成蚜、甘薯天蛾Herse convolvuli L. 2龄幼虫、三化螟Scirpophaga incertulas (Walker)初孵幼虫、菜青虫Pieris rapae (L.) 2龄幼虫和黄曲条跳甲Phyllotreta striolata (Fabricius)成虫都有毒杀效果,其LC₅₀值分别是260.3 mg/L、234.6 mg/L、141.3 mg/L、16.4 mg/L、233.4 mg/L、20.8 mg/L、11.7 mg/L和148.4 mg/L。根甲醇提取物对甘薯天蛾3龄幼虫24 h的触杀和胃毒毒力LC₅₀值分别为101.6 mg/L和234.9 mg/L。此外,亚致死剂量的根甲醇提取物对甘薯天蛾3龄幼虫还有拒食和抑制生长发育的作用。从根中分离和鉴定了3个化合物,即鱼藤酮、6a,12a-脱氢鱼藤素和β-谷甾醇。鱼藤酮和6a,12a-脱氢鱼藤素对三化螟初孵幼虫表现出毒杀活性,24 h的LC₅₀值分别是2.6 mg/L和5.3 mg/L。结论为：亮叶中南鱼藤仅根为活性部位,该甲醇提取物对棉蚜等多种害虫有活性,其主要作用方式为触杀和胃毒,鱼藤酮和6a,12a-脱氢鱼藤素是根中的主要杀虫活性成分。     

瑞香狼毒根提取物对山楂叶螨的生物活性

采用不同的生物活性测定方法比较了瑞香狼毒(Stellera chamaejasme L.)根部4种不同溶剂提取物的杀螨活性。结果表明,瑞香狼毒根提取物对山楂叶螨(Tetranychus viennensis Zacher)有很好的触杀和内吸活性。在触杀活性测试中,石油醚提取物和氯仿提取物的杀螨活性最高;在内吸作用中,乙醇、氯仿和石油醚提取物的杀螨活性均较高,杀螨效果显著。在对石油醚提取物的不同溶剂萃取物进行生物活性追踪测定中发现,石油醚萃取物和氯仿萃取物具有较高的生物活性,浓度为0.6 g.L-1,山楂叶螨的24 h校正死亡率分别达到93.22%和79.66%。     

Growth and invasive potential of Sapium sebiferum (Euphorbiaceae) within the coastal prairie region: the effects of soil and moisture regime

The introduced tree Sapium sebiferum (Euphorbiaceae) is considered a serious threat to the preservation of the coastal prairie region of Louisiana and Texas, although it is currently uncommon in the western part of the region. The objective of this study was to evaluate the potential effects of location, soils, and available moisture on the growth and survival of S. sebiferum in coastal prairie. In a field experiment, S. sebiferum mortality was significantly greater at a western site than at central and eastern sites. The greatest mortality and least growth of surviving plants occurred on a soil from the western region, regardless of site. A greenhouse study also found that S. sebiferum growth was lowest on the western soil. Watering frequency significantly affected S. sebiferum growth, except on the western soil. Sapium sebiferum growth responded to both nitrogen and phosphorus additions for all soils. Soil analyses revealed the highest sand, sodium, and phosphorus contents, and much higher electrical conductivity in the western soil. It is concluded that the soil examined from the western region is unfavorable for S. sebiferum growth, though not to the extent to preclude S. sebiferum completely. Evidence suggests that soil salinity may be the primary cause of the poor S. sebiferum growth at the western site.     

Pest-managing activities of plant extracts and anthraquinones from Cassia nigricans from Burkina Faso

Insecticidal activity of eight plants collected from Burkina Faso was studied using mosquito (Ochlerotatus triseriatus), Helicoverpa zea and Heliothis virescens larvae and adult white fly (Bemisia tabaci). The n-hexane, ethyl acetate and methanol extracts of Pseudocedrela kotschyi, Strophantus hispidus, Securidaca longepedunculata, Sapium grahamii, Swartzia madagascariensis, Cassia nigricans, Jatropha curcas and Datura innoxia were used in this study. Extracts were tested at 250 microg/mL concentration. All three extracts of C. nigricans, J. curcas (skin and seeds) and D. innoxia exhibited 100% mortality on fourth instar mosquito (O. triseriatus) larvae. In addition, the n-hexane and ethyl acetate extracts of S. hispidus, S. longepedunculata, S. grahamii showed 100% mortality. The ethyl acetate extract of S. madagascariensis was the most active on adult white fly and exhibited 80% mortality. Extracts of all other plants exhibited 30-50% mortality on B. tabaci. In the antifeedant assays against H. zea and H. virescens, the MeOH extracts of C. nigricans, S. madagascarensis and S. hispidus were more effective against H. zea as indicated by 74% larval weight reduction as compared to the control. Since C. nigricans is commonly used in West Africa to protect grain storage from insects, we have characterized the insecticidal components present in its extract. Bioassay directed isolation of C. nigricans leaf extract yielded anthraquinones emodin, citreorosein, and emodic acid and a flavonoid, luteolin. Emodin, the most abundant and active anthraquinone in C. nigricans showed approximately 85% mortality on mosquito larvae Anopheles gambiaea and adult B. tabaci at 50 and 25 microg/mL, respectively, in 24 h. These results suggest that the extract of C. nigricans has the potential to be used as an organic approach to manage some of the agricultural pests.     

Toxicity of botanical insecticides on golden apple snail (Pomacea canaliculata)

The molluscicidal activity of crude extracts from five highly potential plants, Annona squamosa seed, Nerium indicum Leaves, Stemona tuberose root, Cyperus rotundus corm and Derris elliptica root was assessed to Pomacea canaliculata. D. elliptica root and C. rotundus corm extracts showed the highest toxicity against 3-month old snails which have LC50 as 23.68 +/- 2.96 mg/l and 133.20 +/- 7.94 mg/l, respectively. The C. rotundus corm extracts were chosen for detoxification enzyme in vivo assay which shows esterase and glutathione S-transferase activity in stomach, intestinal tracts and digestive glands of survival treated P. canaliculata were inhibited.     

乌桕属植物资源在城市绿化中的应用研究

介绍了乌桕属多种植物的生态分布,阐述了该属植物在城市绿化中的前景;并具体分析了以乌桕和山乌桕（红叶乌桕）为代表的该属植物在城市绿化中的配置原则（色彩适宜性、生境适宜性）及应用模式（自然式配置、规则式配置）。最后,建议在乌桕属植物分布区内的城市绿化中大力推广使用。     

利用植物他感作用灭螺效果的研究

通过调查有螺滩地林下植被的演变和乌柏（Ｓａｐｉｕｍｓｅｂｉｐｅｒｕｍ）、枫杨（Ｐｔｅｒｏｃａｒｙａｓｔｅｎｏｐｔｅｒａ）等滩地造林树种的灭螺效果发现,鸡矢藤（Ｐａｅｄｅｒｉａｓｃａｎｄｅｎｓ）、水芹（Ｏｅｎａｎｔｈｅｊａｖａｎｉｃａ）的个体数量与钉螺的数量呈正相关关系,Ｘ２分别为１２．８和１１．２（ａ＜０．０２）,而益母草（Ｌｅｏｎｕｒｕｓａｒｔｅｍｉｓｉａ）、问荆（Ｅｑｕｉｓｅｔｕｍａｒｖｅｎｓｅ）、酸模叶蓼（Ｒｕｍｅｘａｃｅｔｏｓａ）、打碗花（Ｃａｌｙｓｔｅｇｉａｈｅｄｅｒａｃｅａ）、紫云英（Ａｓｔｒａｇａｌｕｓｓｉｎｉｃｕｓ）等与钉螺的数量呈负相关关系（ａ＜０．０２）经过一个汛期,枫杨、乌柏叶片使钉螺死亡率从草滩对照的２％升至４３．３％和４４．１％     

中国乌桕品种资源的调查研究

本文报道对我国１６省８２县乌桕主产区进行乌桕品种资源调查的结果。通过性状比较研究划分为４４个农家品种和１１个无性系品种,并描述了这些品种的分布和性状。     

提高乌桕林经济效益的试验研究

本文报道提高乌桕林经济效益的研究成果。采取垦复、中度修剪、林下套种春花生或马铃薯等作物,适当施肥等综合抚育技术,低产乌桕林的经济效益可提高10倍以上。     

Effects of simulated herbivory and resources on Chinese tallow tree (Sapium sebiferum, Euphorbiaceae) invasion of native coastal prairie

Trade-offs associated with maintaining herbivory resistance and herbivory tolerance are frequently inferred in plant life histories. Invasive success for many non-native plants is often attributed to novel resistance that repels native herbivores. Chinese tallow tree (Sapium sebiferum, Euphorbiaceae) is a non-native invader that threatens ecosystems throughout the southeastern United States, including imperiled coastal prairie regions. Low herbivore loads due to costly resistance are generally assumed to give Sapium a competitive advantage over native plants. We predicted that if Sapium experienced higher damage levels it would show significant decreases in growth and reduced ability to compete with native prairie vegetation. We conducted full-factorial, paired greenhouse and field experiments designed to assess the effects of simulated leaf herbivory on Sapium growth in the presence of prairie vegetation at different levels of light and nitrogen. Contrary to our expectations, neither low-intensity, chronic defoliation nor high-intensity, acute defoliation negatively affected Sapium seedlings in any resource combination in either experiment. These studies reveal that Sapium possesses considerable phenotypic plasticity, and herbivory tolerance is a newly appreciated trait that likely contributes to its invasive potential.     

涝渍胁迫对不同树种生长和能量代谢酶活性的影响

为了解涝渍条件下不同树种的耐涝性和适应性,通过田间模拟试验,分析了涝渍胁迫对1年生落羽杉、美国山核桃和乌桕实生苗生长及能量代谢酶的影响.试验分为对照、渍水和淹水3个处理,处理时间为60 d.结果表明：在渍水和淹水条件下,3种树种的相对生长率均表现为落羽杉>美国山核桃>乌桕,落羽杉耐涝性最强,乌桕耐涝性最弱.涝渍条件下,3种树种的根冠比显著增加,更多的光合产物被分配到根系.3树种乙醇脱氢酶和乳酸脱氢酶活性显著升高,其中耐涝性强的落羽杉增加幅度不大,但一直维持在较高水平;而乌桕和美国山核桃在处理初期增幅较大,在处理后期呈下降趋势.3种树种的苹果酸脱氢酶、磷酸己糖异构酶和葡萄糖-6-磷酸脱氢酶-6-磷酸葡萄糖酸脱氢酶的活性均低于对照,其中落羽杉降幅最低,淹水条件下分别下降35.6%、21.0%和22.7%.耐涝性强的树种能够通过自身的调节,维持各种能量代谢途径的强度,为树种在低氧条件下的生命活动提供能量,进而维持一定的生长量.     

Assessing the Potential of Entomopathogenic Nematodes to Control the Grape Root Borer Vitacea polistiformis (Lepidoptera: Sesiidae) Through Laboratory and Greenhouse Bioassays

Seventeen entomopathogenic nematode species and strains were evaluated for virulence to the grape root borer, Vitacea polistiformis (Harris) in laboratory and greenhouse bioassays. Heterohabditis bacteriophora strain GPS11 and H. zealandica strain X1 produced a larval mortality rate of over 85% of larvae embedded in the root cambium in laboratory bioassays. The nematode species H. marelata and H. bacteriophora strain Oswego produced mortality rates of over 75%. Of the Steinernema species tested, S. carpocapsae strain 'All' performed the best with a mortality rate of 69%. All other nematode species and strains tested, with the exception of S. bicornutum , produced some degree of larval mortality. In the greenhouse bioassays, 93% control was achieved with H. zealandica strain X1 applied at 4 ×109 infective juveniles (IJs) acre1 -1 (9.88 ×10 9 IJs ha -1 ). H. bacteriophora strain GPS11 successfully reproduced in grape root borer larvae. The numbers of IJs produced within infected larvae were related to larval size. The survival rate of neonate larvae on grape root sections was 61%, which thus provides a means to rear the neonate larvae for bioassays.