三江源区"黑土型"退化草地垂穗披碱草人工草地毒杂草危害性分析

通过对三江源区人工草地常见三种毒杂草的危害性研究得知:就植物群落而言,甘肃马先蒿对垂穗披碱草的危害性最大,铁棒锤居中,黄帚橐吾较轻;就植物地上生物量而言,铁棒锤对垂穗披碱草的危害性最大,甘肃马先蒿次之,黄帚橐吾较轻。甘肃马先蒿、铁棒锤、黄帚橐吾的入侵,促使人工草地的逆向演替,导致了人工草地的极度退化。     

天祝天然草地3种有毒植物提取物对粘虫的生物活性

测定了3种有毒植物露蕊乌头,铁棒槌和马先蒿的4种溶剂的提取物对粘虫的杀虫活性。结果表明：露蕊乌头甲醇、乙醇提取物对粘虫均具有一定的触杀活性,LC50分别为3．63、5．79g／L;露蕊乌头甲醇提取物,马先蒿丙酮提取物和铁棒槌甲醇提取物对粘虫的胃毒活性表现较强,杀虫活性LC50分别为2．13,2．82和3．22g／L,马先蒿和铁棒槌的石油醚提取物对粘虫无胃毒活性。3种植物的4种溶剂的提取物对粘虫均表现出一定的拒食活性,其中甲醇提取物的拒食活性都较高,露蕊乌头甲醇提取物对粘虫的拒食活性明显高于其他提取物,当质量浓度达到0．2g／mL时,拒食率为97．6％。而3种植物石油醚提取物的拒食活性均较差。     

3种橐吾属植物提取物的杀虫抑菌活性

黄帚橐吾（Ligularia virgaurea）、箭叶橐吾（L. sagitta）和藏橐吾（L. rumicifolia）均为青藏高原东缘退化高寒草原生态系统的典型毒杂草。本研究从“变害为利”的角度出发,通过测定和对比3种植物提取物对粘虫（Mythimna separate）幼虫的生物活性、对尖孢镰刀菌（Fusarium oxysporum）菌丝生长的影响,探索其生物农药潜力开发价值。研究结果表明：3种橐吾属植物提取物对受试害虫均有较强的胃毒、触杀和拒食作用,表现为藏橐吾>黄帚橐吾>箭叶橐吾。藏橐吾提取物浓度较低时(5 mg·mL^-1),对粘虫幼虫的胃毒7 d累计校正死亡率和触杀7 d累计校正死亡率就分别在70%和50%以上;黄帚橐吾提取物浓度在10 mg·mL^-1以上时,对粘虫幼虫的胃毒7 d累计校正死亡率和触杀7 d累计校正死亡率才能达到70%和50%;而箭叶槖吾提取物在20 mg·mL^-1时对粘虫幼虫的胃毒7 d累计校正死亡率和触杀7 d累计校正死亡率仍都不超过50%。此外,浓度高于2.5 mg·mL...     

黄帚橐吾乙醇提取物对小鼠的急性毒性试验

黄帚橐吾(Ligularia virgaurea)是一种在甘南草原上广泛分布的毒杂草,但同时其乙醇提取物有很强的生物农药活性,具备开发成为生物农药的潜力。本研究通过昆明小鼠(Mus musculus)的经皮、经口急性毒性试验对黄帚橐吾乙醇提取物的安全性进行评估。结果显示,黄帚橐吾乙醇提取物对小鼠的经皮急性毒性半致死剂量LD5030g·kg-1,经口急性毒性LD50为6.983 1g·kg-1,均符合低毒农药登记的毒性标准,可以按照低毒农药进行开发应用。     

新疆伊犁草原毒害草种类及其发生与危害

为查明新疆伊犁毒害草种类,2003-2009年采取普查和随机调查的方法对中国新疆伊犁河谷的天然草地进行了调查。结果表明,毒害草植物有12个科、104个种,侵害面积73万hm2,分布在整个伊犁河谷草原;危害严重的有白喉乌头(Aconitumleucostomum)、准噶尔乌头(A.soongaricum)、纳里橐吾(Ligularianarynensis)、狼毒(Stellerachamaejasme)、野麻(Leonurus heterophyllus)、苦豆子(Sophora alopecuroides)、针茅(Stipacapillata)、水杨梅(Geumaleppicum)、大戟(Eupborbiaspp.)、大蓟(Cirsiumjaponicum)和骆驼蓬(Peganumharmala)等;主要优势种是白喉乌头、准噶尔乌头和纳里橐吾,100 m2的样地中,2003年纳里橐吾平均为210株,2006年平均为1 045株,2008年为2 347株;2003年白喉乌头平均为48株,2006年平均为288株,2008年平均为366株;毒害草在新疆伊犁草原正呈快速蔓延之势。新疆伊犁草原毒害草分布具有明显的区域性和地域性,且毒害草萌发早、生长速度快,并有多种繁殖和传播方式,危害性大。     

黄河源区"黑土滩"退化草地群落类型多样性及其群落结构研究

调查了黄河源区高寒草甸极度退化产物“黑土滩”植被群落类型多样性及其群落结构特征。结果表明,分布在黄河源区高寒草甸上的“黑土滩”草地植被可分为7个类型,分别为:黄帚橐吾 铁棒棰群落、白苞筋骨草群落、铁棒棰群落、西伯利亚蓼 鹅绒委陵菜群落、摩苓草群落、甘青微孔草群落和甘肃马先蒿群落。从群落结构和已有的研究结果看,黄河源区所有类型的“黑土滩”草地都完全失去了牧用价值,短期内自然恢复的物质基础也已丧失,该类草地的恢复治理必须通过人工植被的重建来实现。     

黄南州天然草地毒草调查与防治

采用现场调查和资料收集相结合的方法,对黄南州危害家畜最严重的4种主要毒草黄花棘豆、狼毒、醉马草、黄帚橐吾的分布面积、地理分布、生长特性、危害及其防除对策做了重点阐述,并对如何综合防治和利用提出了建议.     

灰绿黄堇提取物对粘虫的生物活性研究

采用虫体浸渍法、夹毒叶碟法等方法研究了灰绿黄堇提取物对粘虫(Mythimna separate)的杀虫活性和作用方式。结果表明,灰绿黄堇不同极性溶剂粗提物对粘虫3龄幼虫的触杀作用以甲醇粗提物最强,校正死亡率为15.5%;甲醇粗提物不同极性溶剂萃取物以氯仿萃取物触杀作用最强,校正死亡率可达87.5%,其致死中质量浓度为13.07 g/L;氯仿萃取物对粘虫3龄幼虫具有很强的生长发育抑制作用和胃毒作用,生长发育抑制率和校正死亡率分别为88.66%和91.38%。     

黄南州天然草地毒草调查与防治

采用现场调查和资料收集相结合的方法,对黄南州危害家畜最严重的4种主要毒草黄花棘豆、狼毒、醉马草、黄帚橐吾的分布面积、地理分布、生长特性、危害及其防除对策做了重点阐述,并对如何综合防治和利用提出了建议。     

西藏草地有毒植物分布调查

采用文献收集和实地调查结合的方法对西藏草地有毒植物的种类、生态分布进行了调查分析。结果表明,西藏草地有毒植物共计178种,分属51科,113属;其中冰川棘豆(Oxytropis Glacialis)、毛瓣棘豆(O.Sericopetala)、茎直黄芪(Astragaluo Strictus)、直立黄芪(A.absurgens)、狼毒(Stellera Chamaejasme)、伏毛铁棒锤(Acontium flavum)、露蕊乌头(A.gymnanodrum)、工布乌头(A.kongboense)、铁棒锤(A.pendulum)等有毒植物的分布较广、危害较大。并针对西藏草地主要有毒植物防治方法及利用价值进行定位,提出了牧民认知-放牧管理-毒草监测-开发利用四位一体的毒草防治利用及生态保护对策。     

甘青赛莨菪粗提物的杀虫活性研究

采用虫体浸渍法和叶碟浸渍法研究了甘青赛莨菪粗提物对粘虫、菜青虫和麦长管蚜虫的杀虫活性。试验结果表明,甘青赛莨菪叶甲醇粗提物对粘虫5龄幼虫的触杀活性最强,其次为茎和根皮甲醇粗提物,稀释5倍液的校正死亡率分别为28.09%,18.30%和17.07%。叶甲醇粗提物对4龄菜青虫的触杀活性最强,其次为茎和根皮甲醇粗提物,稀释10倍液的校正死亡率分别为66.67%,64.29%和60.00%。叶、茎和根皮甲醇粗提物对4龄菜青虫的拒食活性均很弱,对麦长管蚜具有一定的触杀活性,对棉蚜和桃蚜无触杀活性。     

红蓼提取物对13种农业害虫触杀活性的研究

关于红蓼提取物对农业害虫的触杀活性,国内外研究甚少。研究红蓼提取物对害虫的触杀活性,可为利用该植物研制新型植物源杀虫剂提供理论依据。本研究采用浸渍法测定了红蓼提取物对害虫的触杀活性,结果表明,红蓼种子乙酸乙酯萃取物对粘虫、菜粉蝶、棉铃虫、甘蓝夜蛾、甜菜夜蛾和小地老虎4~5龄幼虫具有很强的触杀活性,在16.80 g/L浓度下的校正死亡率在87.50%~100%;对小菜蛾3龄幼虫也具有很强的触杀活性,在21.00 g/L浓度下的校正死亡率为92.85%;秋季茎秆乙酸乙酯萃取物对菜粉蝶4龄幼虫和粘虫5龄幼虫具有很强和较强的触杀活性,在33.60 g/L浓度下的校正死亡率分别为100%和59.20%。盛花期茎秆石油醚粗提物对棉蚜具有较强的触杀活性,在0.27 g/L浓度下的校正死亡率为51.65%。盛花期花石油醚和甲醇粗提物对朱砂叶螨具有很强的触杀活性,在0.13和1.15 g/L浓度下的校正死亡率均高达100%。     

节裂角茴香几种溶剂提取物对粘虫的作用方式研究

本研究以节裂角茴香为对象,采用室内生物测定方法,开展了不同提取方法(恒温振荡法和索氏抽提法)和不同溶剂(乙醇、甲醇、正己烷、二氯甲烷)所得的8种提取物对粘虫的作用方式的研究。结果表明,节裂角茴香最佳杀虫提取方法与溶剂分别为索氏抽提法及乙醇;其提取物对3龄粘虫幼虫具有较强的拒食和生长发育抑制作用,24和48 h的拒食率均在70%以上,乙醇提取物拒食率最高达到90.78%,4种溶剂提取物处理粘虫24 h的生长发育抑制率为74.21%~91.45%,乙醇提取物48 h为87.00%,生长发育速度缓慢,最终化蛹率为23.33%;8种提取物对粘虫的触杀和胃毒作用均较弱,乙醇提取物48 h触杀和胃毒校正死亡率最高,为33.33%和23.3%;且节裂角茴香对粘虫的拒食活性物质主要集中在植株地上部分。     

马铃薯无光干芽和花乙酸乙酯粗提物杀虫活性的研究

关于马铃薯芽和花的杀虫活性研究,国内外未见文献报道。研究马铃薯无光干芽和花的杀虫活性及其对粘虫的作用方式,可为利用无光干芽和花创制新型植物源杀虫剂提供线索和理论依据。本研究采用虫体浸渍法和夹毒叶碟法测定了庄薯3号马铃薯无光干芽和花乙酸乙酯粗提物的杀虫活性。结果表明,庄薯3号马铃薯无光干芽和花乙酸乙酯粗提物对粘虫幼虫具有很强的触杀作用,稀释5倍液的校正死亡率分别为52.0%和61.36%。无光干芽和花乙酸乙酯粗提物对粘虫幼虫具有很强的生长发育抑制作用,处理后1,2,3,4,5,6 d的生长发育抑制率分别为100%和100%,76.92%和61.54%,66.67%和59.26%,70.27%和45.95%,72.55%和49.02%,67.12%和35.62%;具有很强的麻醉作用,1 h内的麻醉率分别为68.0%和66.0%,麻醉作用的回归方程分别为Y=2.0542+3.1331X和Y=3.0114+2.3334X,苏醒中时RT₅₀分别为8.71和7.12 h;对小菜蛾、菜粉蝶、大菜粉蝶和云斑粉蝶幼虫具有很强的触杀作用,稀释5倍液(小菜蛾4倍液)的校正死亡率分别为75.0%和58.33%,87.50%和95.0%,100%和93.33%,100%和100%;对萝卜蚜均具有很强的触杀作用,稀释30倍液的校正死亡率分别高达98.52%和97.79%。     

苏云金芽孢杆菌YJ-2000菌株对家蚕安全性和杀虫活性的评价

应用时间-剂量-死亡率模型就苏云金芽孢杆菌(Bacillus thuringiensis)YJ-2000菌株对6种鳞翅目昆虫的杀虫活性作了初步评价。该菌株对家蚕基本无毒性,而对蔬菜害虫小菜蛾、菜粉蝶,水稻害虫三化螟、二化螟,桑树害虫桑螟幼虫均有不同程度的毒性,其中对小菜蛾和菜粉蝶的毒性最强;幼虫死亡率可高达100％。该菌株是对家蚕安全而对其它鳞翅目害虫具杀虫活性的特异性菌株,有望用于养蚕地区桑园及其邻近作物的鳞翅目害虫防治。     

In vitro effects of four tropical plants on three life-cycle stages of the parasitic nematode, Haemonchus contortus

Alcoholic extracts of four tropical plants (Zanthoxylum zanthoxyloides, Newbouldia laevis, Morinda lucida and Carica papaya) were screened in vitro for potential anti-parasitic effects against eggs, infective larvae and adult Haemonchus contortus. Significant effects were obtained with all four plants but differences were observed depending on the parasitic stage. The effects of the four plant extracts were similar on egg hatching and were dose dependent. In contrast, no dose-response relationship was found for infective larvae and adult worms, although more potent effects were usually observed with the highest concentrations. Using a larval inhibition migration test, extracts of fagara (Z. zanthoxyloides) were found to be less active against Haemonchus infective larvae than were the other plants. N. laevis was found to be highly and rapidly effective against adult worms. Overall, these in vitro results suggest that these four plants, traditionally used by small farmers in Western Africa, do possess anti-parasitic properties. These effects remain to be confirmed through in vivo studies.     

The efficacy of some wild medicinal plant extracts on the survival and development of third instar larvae of <Emphasis Type="Italic">Chrysomyia albiceps</Emphasis> (Wied) (Diptera: Calliphoridae)

Four crude wild plants extract of Artemisia herba-alba Asso, Artemisia monosperma Del., Euphorbia aegyptiaca Boiss. and Francoeuria crispa (Forsk.) extracted with four successive solvents; hexane, diethyl ether, ethyl acetate and ethanol were evaluated against the third instar larvae of Chrysomyia albiceps using dipping and thin film techniques. In dipping technique, larvae were immersed in the concentrations of plant extracts for 30 seconds. However, in thin film technique, larvae were exposed to thin layer from each plant extract in the Petri-dishes. Results showed that all extracts had toxic effects on larvae in both two treatments. Hexane and diethyl ether extracts of A. herba-alba and ethyl acetate extract of A. monosperma recorded the highest effect in both two treatments. Ethanol extracts of E. aegyptiaca and A. monosperma were the highest in dipping and thin film treatments, respectively. In dipping treatment, most plant extracts revealed extending effect on pupae especially while in thin film treatment most larvae which succeeded to develop to pupae produced normal flies. Deformed pupae were only recorded with the high concentration of diethyl extracts of A. herba-alba. Hexane, diethyl ether and ethyl acetate extracts of F. crespa only produced low percentages of deformed flies. Histological examination conducted on larvae confirmed that extracts in thin film treatment penetrated to the gut and destroyed its epithelial cells and wall. It concluded that the crude extracts of the four tested plants can be used in controlling of C. albiceps larvae while hexane extracts of E. aegyptiaca, A. herba-alba and A. monosperma are considered the most promising plant preparations against the larvae by using thin film technique.     

Partial biochemical and serological characterization of exsheathing fluid and somatic extracts of infective larvae and adult females of Haemonchus contortus.

Exsheathing fluid from infective larvae of Haemonchus contortus may contain antigens which induce protective immunity upon infection in sheep. In this study, a rapid method of preparing exsheathing fluid was used to determine its biological activity, purity and antigenic complexity. Protein in exsheathing fluid ranged from 21-59.5 micrograms/mL and no carbohydrate was detected. Gel filtration showed a single broad peak which retained biological activity and polyacrylamide gel electrophoresis demonstrated a single band staining with Coomassie blue. Biological activity of exsheathing fluid was present in extracts of infective larvae but not in extracts of exsheathed larvae or in extracts of adult female H. contortus. Rabbit antiserum against exsheathing fluid proteins cross-reacted with infective larvae extracts but not with adult female worm extracts. Immunoelectrophoresis of exsheathing fluid proteins against this antiserum showed a single polydisperse precipitin line. Thus, exsheathing fluid produced by the rapid method is a pure preparation of a biologically active and antigenically simple material suitable for further studies of protective immunity in sheep to H. contortus.     

菊苣叶提取物对粘虫的生物活性研究

为研究菊苣叶提取物的杀虫活性,采用冷浸法和超声波混合提取法得到菊苣叶提取物,对3及4龄粘虫分别用饲喂称重法和叶碟添加法进行毒力测定。结果表明,各有机溶剂提取物处理的幼虫体重均显著低于对照组(P＜0.05);乙醇和乙酸乙酯提取物处理组的幼虫期比对照组延长了4.3 d;各有机溶剂提取物处理组中,乙酸乙酯提取物死亡率最高,为57.78%,其化蛹率最低,仅为46.67%;各处理组蛹重均显著大于对照组(P＜0.05) ;乙醇和乙酸乙酯提取物处理组粘虫的拒食率高达80%以上。