楝科植物柠檬素类化合物杀虫活性研究的新进展(英文)

植物中的次生代谢物是植物性杀虫剂的活性有效成分。关于来自楝科植物的柠檬素类化合物杀虫活性的研究近年来又有了新进展。这些化合物对许多种重要害虫具有驱避、拒食、毒杀、抑制生长发育等活性。来自楝属、印楝局的植物在杀虫活性、有活性种类数量方面高于其它属,米仔兰属、鹧鸪花属和香椿属的植物也有较高的杀虫活性。柠檬素类化合物的杀虫作用机制在本文中也做了综述。     

植物精油对土耳其扁谷盗的驱避和熏蒸活性研究

本文研究了34种植物精油对土耳其扁谷盗成虫的驱避和熏蒸毒杀活性。结果表明,肉桂精油对土耳其扁谷盗成虫具有良好的驱避活性,24-48 h内,75%的个体选择了未添加植物精油的小麦;72 h后选择对照组的土耳其扁谷盗成虫降至63.33%,但仍有显著的驱避活性。孜然、松油和黑胡椒精油则对土耳其扁谷盗成虫表现出良好的引诱活性。在34种供试植物精油中,大蒜和芥末精油对土耳其扁谷盗成虫表现出强烈的熏蒸毒杀作用。当植物精油体积分浓度为10μL/L时,这两种植物精油在48 h内对供试害虫的校正死亡率保持在98%以上。进一步的毒力测试结果表明,在24 h、48 h及72 h处理时间下,大蒜精油对土耳其扁谷盗成虫的LC_(50)值分别为0.61、0.59及0.49μL/L,而芥末精油在相同处理时间条件下的LC_(50)值分别为4.35、4.28及4.16μL/L,大蒜精油对土耳其扁谷盗具有更强的熏蒸毒杀活性。     

烟蓟马成虫对不同植物挥发物的行为选择

【目的】评价不同植物挥发物对烟蓟马Thrips tabaci雌性成虫的行为调控作用,解析烟蓟马成虫嗅觉识别行为,为研发成虫引诱剂或驱避剂提供科学依据。【方法】利用嗅觉行为测定装置测试烟蓟马雌性成虫对不同种类、不同浓度植物挥发物的室内选择行为,筛选出具有高引诱或驱避活性的挥发物。【结果】与溶剂正己烷相比,烟蓟马雌性成虫对浓度为1μg/μL的γ-癸酸内酯、(+)α-蒎烯、芳樟醇、2-乙酸苯乙酯、(-)α-蒎烯没有显著的行为选择（P>0.05）,而壬醛、马鞭草烯酮、香茅醛、橙花醇和桉树脑对烟蓟马表现出显著的吸引作用（P<0.05）,4-乙酰吡啶、邻茴香醛、δ-癸酸内酯、顺-3-己烯醇、香叶醇和1-辛烯-3-醇的吸引作用极显著（P<0.001）;但水杨醛、香芹酚、顺茉莉醛、丁香酚和对烯丙基苯甲醚对烟蓟马表现出显著的驱避作用（P<0.05）,水杨酸甲酯、茉莉酸甲酯、百里酚和异戊醛4种挥发物具有极显著的驱避作用（P<0.001）。同时,随着测试浓度的增加,大部分挥发物对烟蓟马雌性成虫的吸引或驱避作用明显增强。【结论】δ-癸酸内酯、香叶醇、1-辛烯-3-醇、邻茴香醛和4-乙酰吡啶对烟蓟马雌性成虫具有强烈吸引作用,水杨酸甲酯、茉莉酸甲酯和百里酚则具有明显驱避效应,为开发烟蓟马行为调控剂奠定了重要基础。     

八角叶片提取物对榕管蓟马成虫的生物活性

本文采用"Y"型管法和三角瓶熏蒸法研究了八角叶的4种溶剂提取物对榕管蓟马成虫的驱避和杀虫作用。结果表明,八角叶的4种溶剂提取物对榕管蓟马成虫均具有驱避和杀虫作用。其中,丙酮、无水乙醇和乙酸乙酯3种溶剂提取物的驱避和杀虫作用较强,浓度为1.60mg/cm2处理的驱避等级均达到Ⅳ级,而相同浓度石油醚提取物的驱避等级仅为Ⅱ级。在杀虫活性方面,用3.54mg/cm2提取物处理36h后,榕管蓟马成虫的校正死亡率除石油醚提取物外均达93.67%以上。另外,八角叶4种溶剂提取物对榕管蓟马成虫的LC50测定表明,丙酮提取物对榕管蓟马成虫的杀虫效果最好。本文结果将为榕管蓟马成虫的防治及植物源杀虫剂的开发提供实验基础。     

4种植物精油对金银花贮藏期害虫锯谷盗的生物活性北大核心CSCD

采用滤纸药膜法和广口瓶熏蒸法,在室内测定了大蒜、生姜、花椒和八角茴香4种植物精油对金银花贮藏期害虫锯谷盗的生物活性。结果表明,4种植物精油对锯谷盗成虫均具有一定的驱避活性和熏蒸活性,平均驱避率分别为70.71%、60.64%、53.78%和66.33%,平均校正死亡率分别为60.47%、51.71%、47.01%和56.28%,差异达显著水平。4种植物精油的不同浓度和不同作用时间对锯谷盗成虫的驱避活性有显著差异,随着植物精油浓度的降低和作用时间的延长,各植物精油的驱避活性逐渐降低,浓度和时间的交互作用对驱避活性无显著影响。4种植物精油的浓度、不同作用时间以及它们的交互作用对锯谷盗成虫的熏蒸活性有显著影响,随着植物精油浓度的降低,熏蒸活性逐渐降低,随着作用时间的延长,熏蒸活性逐渐增强。进一步的毒力分析表明,大蒜精油的毒力最强,12 h的LC50值为6.01μL/L,随时间的延长,各植物精油的熏蒸毒力明显增强。这说明4种植物的精油对金银花贮藏贮藏期害虫锯谷盗具有一定的生物活性,具有开发为新型无公害杀虫剂的潜力。     

4种植物精油对金银花贮藏期害虫锯谷盗的生物活性

采用滤纸药膜法和广口瓶熏蒸法,在室内测定了大蒜、生姜、花椒和八角茴香4种植物精油对金银花贮藏期害虫锯谷盗的生物活性。结果表明,4种植物精油对锯谷盗成虫均具有一定的驱避活性和熏蒸活性,平均驱避率分别为70.71%、60.64%、53.78%和66.33%,平均校正死亡率分别为60.47%、51.71%、47.01%和56.28%,差异达显著水平。4种植物精油的不同浓度和不同作用时间对锯谷盗成虫的驱避活性有显著差异,随着植物精油浓度的降低和作用时间的延长,各植物精油的驱避活性逐渐降低,浓度和时间的交互作用对驱避活性无显著影响。4种植物精油的浓度、不同作用时间以及它们的交互作用对锯谷盗成虫的熏蒸活性有显著影响,随着植物精油浓度的降低,熏蒸活性逐渐降低,随着作用时间的延长,熏蒸活性逐渐增强。进一步的毒力分析表明,大蒜精油的毒力最强,12 h的LC50值为6.01μL/L,随时间的延长,各植物精油的熏蒸毒力明显增强。这说明4种植物的精油对金银花贮藏贮藏期害虫锯谷盗具有一定的生物活性,具有开发为新型无公害杀虫剂的潜力。     

嗜食植物与非嗜食植物对西花蓟马成虫寄主选择性的影响

【目的】西花蓟马是世界性害虫,利用西花蓟马对寄主植物嗜食性的差异,通过驱避作用防控西花蓟马,能够为绿色治理提供依据。【方法】在西花蓟马嗜食的甘蓝和非嗜食的大蒜上互喷汁液,采用黄瓜+甘蓝、黄瓜+大蒜2种相间种植方式,研究它们对西花蓟马寄主选择性的影响。【结果】在甘蓝上喷洒大蒜汁液后,甘蓝叶片上西花蓟马的虫量和产卵量均明显减少。大蒜汁液浓度越高,减少得越多;在大蒜上喷洒甘蓝汁液后,大蒜植株上西花蓟马的虫量和产卵量明显增加,且增加程度与甘蓝汁液的浓度呈正相关。黄瓜和甘蓝相间排列时,西花蓟马在黄瓜叶片上的数量与单作黄瓜叶片上无明显差异;但黄瓜和大蒜相间排列时,西花蓟马在黄瓜上的数量明显高于单作黄瓜上的虫数,多52.4%。【结论】在嗜食寄主植物上喷洒非嗜食植物汁液或间作非嗜食的寄主可以明显减少西花蓟马的选择性。研究结果为利用非嗜食植物挥发物防控西花蓟马提供了理论依据和新的方法。     

香茅精油对桔小实蝇产卵驱避作用及其化学成份分析

研究了香茅Cymbopogon nardus精油对桔小实蝇Bactrocera dorsalis (Hendel)的产卵驱避作用及其化学成分。结果表明,香茅精油对桔小实蝇产卵具有一定的驱避作用,不同浓度香茅精油处理芒果上的产卵量均显著低于对照,且随着香茅精油浓度的提高其产卵量逐渐减少,当浓度为10000μg/mL时,产卵驱避率为70.06%。采用气相色谱—质谱联用(GC-MS)技术分析了香茅精油的化学成份,结果发现该精油挥发物中含量较高的是3-蒈烯,香茅醛,香叶醇,香茅醇,柠檬烯。     

非嗜食植物次生物质对小菜蛾产卵驱避和拒食作用的研究

基于植物与昆虫的协同进化理论,利用25科37种小菜蛾非嗜食植物的茎、叶、花或根的乙醇提取物,研究其对小菜蛾成虫的产卵驱避作用和对幼虫的拒食作用。结果表明,供试植物提取物对小菜蛾有不同程度的产卵驱避和拒食效果,羊蹄甲、细叶桉、飞扬草、假连翘、花椒、荷花玉兰、烟草的乙醇提取物对小菜蛾成虫产卵有较好的驱避效果,驱避率均达80％以上,一品红、构树、艾蒿、茶枯、垂柳、飞扬草、羊蹄甲、狗尾草的乙醇提取物对小菜蛾幼虫有较好的拒食作用,48h的拒食率达80％以上。     

16种植物乙醇提取物对桔全爪螨的生物活性测定

测定了16种植物乙醇提取物对桔全爪螨成螨的产卵忌避、驱避及毒杀生物活性。试验结果表明,海芋、山苍子及盐肤木茎叶的乙醇提取物有明显的产卵忌避作用,忌避率在96.43%以上;山苍子、枫香植物乙醇提取物对桔全爪螨成螨的驱避作用明显,驱避率在80%以上;山苍子、盐肤木茎叶、牡荆和幌伞枫提取物对桔全爪螨成螨的毒杀效果明显,在处理72h后,死亡率在92%以上。     

Influence of salicylaldehyde and methyl salicylate on post-landing behaviour of Frankliniella occidentalis Pergande

This study investigates behavioural responses of adult western flower thrips (Frankliniella occidentalis Pergande; Thysan., Thripidae) females to direct contact with repellent phenylpropanoid plant compounds (salicylaldehyde and methyl salicylate) applied on bean and cucumber leaves. The residence time of F. occidentalis females until take off was significantly shorter on bean or cucumber leaf discs treated with salicylaldehyde at 1% concentration compared with control leaf discs. A methyl salicylate (1%) treatment of cucumber resulted in shorter time periods until thrips took off the treated leaf discs compared with the control leaf discs. In a choice experiment thrips avoided to settle on a 1% salicylaldehyde treatment of bean and cucumber leaf discs for a maximum of 3 h, on a 1% methyl salicylate treatment for a 5‐h period. Within a 24‐h period neither the egg‐laying nor the feeding activity of F. occidentalis was affected after salicylaldehyde application (0.1%, 1%) on bean or cucumber. In contrast, methyl salicylate (1%) applied on bean and cucumber significantly prevented thrips females from oviposition and reduced the percentage of damaged area caused by their feeding activity for 24 h. As olfactory repellent plant volatiles applied on crop plants may elicit diverse post‐landing responses of F. occidentalis, short‐ and long‐term effects should be considered when evaluating the factual applicability of secondary plant compounds in a successful thrips management strategy.     

Effectiveness of aromatic plant species for repelling and preventing oviposition of Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae)

This study assesses the effectiveness of essential oils for repelling whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), and deterring oviposition. We evaluated essential oils from four plants: Curcuma longa (Zingiberaceae), Litsea cubeba (Lauraceae), Piper nigrum (Piperaceae) and Zanthoxylum bungeanum (Rutaceae), under laboratory and glasshouse conditions. In the laboratory, ethanol‐extracted essential oils were applied uniformly on both sides of a tomato leaf in the treatment groups, and the same volume of liquid but without essential oil was used for the control. Results showed that essential oils from L. cubeba, P. nigrum, C. longa and Z. bungeanum provided some repellency of whiteflies and reduced oviposition. Oils from L. cubeba repelled adult females (69.14% and 62.49% repellency at 24 and 48 hr, respectively), and oils from C. longa deterred oviposition (68.46% and 65.94% at 24 and 48 hr exposures, respectively). In the glasshouse, potted tomato plants with eight leaves were sprayed with treatments and control material. Five‐day‐old adult female whiteflies were released in a cage between both pots. Essential oils from L. cubeba repelled females 54.77 at 24 hr and P. nigrum 44.37% at 48 hr whereas oils from P. nigrum reduced oviposition by 43.35 at 24 hr and Z. bungeanum 21.08% at 48 hr, under glasshouse conditions. Essential oils show potential to be used to reduce feeding and oviposition, and thus being important components of integrated pest management programs. However, future research is needed to investigate individual compounds of these oils against whitefly, and to enhance their effectiveness.     

Sesquiterpene Lactones: More Than Protective Plant Compounds With High Toxicity

Sesquiterpene lactones (STLs) constitute a large group of secondary metabolites that are widely distributed in several angiosperm plant families and a few bryophytes, including liverworts. These metabolites are particularly diversified in the family Asteraceae, in which more than 5,000 compounds have been reported so far. In addition to their pharmacological importance and potential therapeutic applications, most STLs display a wide range of protective activities in plants, including acting as anti-herbivory and antimicrobial substances or inhibiting growth of competing plants. These activities are mainly related to their characteristic α,β-unsaturated structural elements, which can participate in Michael-type additions with biological nucleophiles that contain sulfhydryl groups. Supporting the protective roles of STLs, they are mainly located in glandular trichomes of aerial parts because the highly nonspecific toxicity of such compounds necessitates compartmentalization to prevent autotoxicity. However, STLs have also been reported in other aerial and underground organs, where they are assumed to exhibit other biological activities. Recent studies have suggested that these metabolites not only display protective activities due to toxicity but also play key physiological roles in mediating rhizosphere communication among plants, soil microorganisms and plant parasites. STLs have been directly implicated in plant phototropism, resulting in differential growth of a plant organ due to auxin inhibition when accumulated in response to a light stimulus. This review therefore not only highlights the protective roles of STLs in producing plants but also explores the physiological roles of these metabolites, thus providing insights for new research approaches for understanding the roles of STLs in plants and their potential future applications.     

Resistance factors in pepper inhibit larval development of thrips (Frankliniella occidentalis)

The western flower thrips [Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae)] is a major pest in pepper cultivation. Therefore, host plant resistance to thrips is a desirable trait. The objectives of this study were to determine the effect of resistance on the development of thrips and to identify metabolite compounds related to the resistance. Three highly resistant, three medium resistant, and three susceptible pepper accessions were used in this study. Adult and pre‐adult survival, developmental time, and oviposition rate were assessed. Gas chromatography‐mass spectrometry was used to identify compounds that correlate with the level of resistance to thrips. Our results show that resistance of pepper accessions has a significant effect on oviposition rate and larval mortality. Seven compounds were identified that correlate with resistance to thrips and six compounds were identified that correlate with susceptibility to thrips. Some of these compounds, such as tocopherols, were previously shown to have an effect on insects in general. Also, some specific secondary metabolites (alkanes) seem to be more abundant in susceptible accessions and were induced by thrips infestation.     

Intraguild predation among plant pests: western flower thrips larvae feed on whitefly crawlers

Omnivores obtain resources from more than one trophic level, and choose their food based on quantity and quality of these resources. For example, omnivores may switch to feeding on plants when prey are scarce. Larvae of the western flower thrips Frankiniella occidentalis Pergande (Thysanoptera: Thripidae) are an example of omnivores that become predatory when the quality of their host plant is low. Western flower thrips larvae usually feed on leaf tissue and on plant pollen, but may also attack eggs of predatory mites, their natural enemies, and eggs of the two-spotted spider mite Tetranychus urticae Koch (Acari: Tetranychidae), one of their competitors. Here, we present evidence that western flower thrips larvae prey on Trialeurodes vaporariorum Westwood (Hemiptera: Aleyrodidae), another competitor for plant tissue. We tested this on two host plant species, cucumber (Cucumis sativa L.), considered a host plant of high quality for western flower thrips, and sweet pepper (Capsicum annuum L.), a relatively poor quality host. We found that western flower thrips killed and fed especially on whitefly crawlers and that the incidence of feeding did not depend on host-plant species. The developmental rate and oviposition rate of western flower thrips was higher on a diet of cucumber leaves with whitefly crawlers than on cucumber leaves without whitefly crawlers, suggesting that thrips do not just kill whiteflies to reduce competition, but utilize whitefly crawlers as food.     

昆虫对植物次生物质的代谢适应机制及其对昆虫抗药性的意义

植物次生物质(plant secondary metabolites)对昆虫的取食行为、生长发育及繁殖可以产生不利影响,甚至对昆虫可以产生毒杀作用。为了应对植物次生物质的不利影响,昆虫通过对植物次生物质忌避取食、解毒代谢等多种机制,而对寄主植物产生适应性。其中,昆虫的解毒代谢酶包括昆虫细胞色素P450酶系（P450s）及谷胱甘肽硫转移酶（GSTs）等,在昆虫对植物次生物质的解毒代谢及对寄主植物的适应性中发挥了重要作用。昆虫的解毒酶系统不仅可以代谢植物次生物质,还可能代谢化学杀虫剂,因而昆虫对寄主植物的适应性与其对杀虫剂的耐药性甚至抗药性密切相关。昆虫细胞色素P450s和GSTs等代谢解毒酶活性及相关基因的表达可以被植物次生物质影响,这不仅使昆虫对寄主植物的防御产生了适应性,还影响了昆虫对杀虫剂的解毒代谢,因而改变昆虫的耐药性或抗药性。掌握昆虫对植物次生物质的代谢适应机制及其在昆虫抗药性中的作用,对于明确昆虫的抗药性机制具有重要的参考意义。本文综述了植物次生物质对昆虫的影响、昆虫对寄主植物次生物质的代谢机制、昆虫对植物次生物质的代谢适应性对昆虫耐药性及抗药性的影响等方面的研究进展。     

41种植物精油对淡色库蚊的熏蒸活性

为发现具有较高杀蚊活性的精油, 推动植物精油类卫生杀虫剂的创制, 本研究采用三角瓶熏蒸法测定了17科41种植物精油对淡色库蚊Culex pipiens pallens雌成蚊的熏蒸活性, 并进一步采用密闭圆筒法验证其杀虫毒力大小。三角瓶熏蒸法测定表明, 在12 μL/L浓度下, 留兰香油（spearmint oil）、 薰衣草油（lavender oil）、 山苍子油（Litsea cubeba oil）等26种精油均有较强的熏蒸作用, KT₅₀小于15 min。该26种精油用密闭圆筒熏蒸法进一步测定表明, 在浓度为10 μL/L时, 冬青油（wintergreen oil）、 艾叶油（blumea oil）、 薄荷油（peppermint oil）、 桉叶油（Eucalyptus robusta oil）和蓝桉油（E. globulus oil）等植物精油熏蒸活性较强, 其KT₅₀分别为16.91, 21.20, 22.57, 18.43和19.48 min。结果证明冬青油、 艾叶油、 薄荷油、 桉叶油和蓝桉油等5种精油对淡色库蚊具有较强的熏蒸活性, 具备作为淡色库蚊防控剂开发的潜力, 值得进一步研究。     

Antagonistic plant defense system regulated by phytohormones assists interactions among vector insect, thrips and a tospovirus

The western flower thrips (Frankliniella occidentalis) is a polyphagous herbivore that causes serious damage to many agricultural plants. In addition to causing feeding damage, it is also a vector insect that transmits tospoviruses such as Tomato spotted wilt virus (TSWV). We previously reported that thrips feeding on plants induces a jasmonate (JA)-regulated plant defense, which negatively affects both the performance and preference (i.e. host plant attractiveness) of the thrips. The antagonistic interaction between a JA-regulated plant defense and a salicylic acid (SA)-regulated plant defense is well known. Here we report that TSWV infection allows thrips to feed heavily and multiply on Arabidopsis plants. TSWV infection elevated SA contents and induced SA-regulated gene expression in the plants. On the other hand, TSWV infection decreased the level of JA-regulated gene expression induced by thrips feeding. Importantly, we also demonstrated that thrips significantly preferred TSWV-infected plants to uninfected plants. In JA-insensitive coi1-1 mutants, however, thrips did not show a preference for TSWV-infected plants. In addition, SA application to wild-type plants increased their attractiveness to thrips. Our results suggest the following mechanism: TSWV infection suppresses the anti-herbivore response in plants and attracts its vector, thrips, to virus-infected plants by exploiting the antagonistic SA-JA plant defense systems.     

Jasmonate-dependent plant defenses mediate soybean thrips and soybean aphid performance on soybean

Insect herbivores from different feeding guilds induce different signaling pathways in plants. In this study, we examined the effects of salicylic acid (SA)- and jasmonic acid (JA)-mediated defenses on performance of insect herbivores from two different feeding guilds: cell-content feeders, soybean thrips and phloem feeders, soybean aphids. We used a combination of RT-qPCR analysis and elicitor-induced plant resistance to determine induction of SA and JA signaling pathways and the impact on herbivore performance. In the early interaction between the host plant and the two herbivores, SA and JA signaling seems to occur simultaneously. But overall, soybean thrips induced JA-related marker genes, whereas soybean aphids increased SA and ABA-related marker genes over a 24-h period. Populations of both soybean thrips and soybean aphids were reduced (47 and 25 %, respectively) in methyl jasmonate (MeJA)-pretreated soybean plants. SA treatment has no effect on either herbivore performance. A combination pretreatment of SA and MeJA did not impact soybean thrips population but reduced soybean aphid numbers which was comparable with MeJA treatment. Our data suggest that SA–JA antagonism could be responsible for the effect of hormone pretreatment on thrips performance, but not on aphid performance. By linking plant defense gene expression and elicitor-induced resistance, we were able to pinpoint the role for JA signaling pathway in resistance to two herbivores from different feeding guilds.