Screening of crude plant extracts as feeding deterrents of the wireworm, Melanotus communis

Extracts from 78 plant species (24 families) were screened for antifeedant activity against the corn wireworm, Melanotus communis Gyll. (Coleoptera: Elateridae). Five extracts from four families significantly reduced wireworm feeding damage in a series of choice feeding tests. Two extracts, Asclepias tuberosa and Hedera helix, exhibited exceptional levels of feeding deterrency. An x-ray technique indicated that wireworms burrowed indiscriminately between soil containing either of these extracts and surrounding untreated soil, but were found more frequently in the untreated areas.

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Résumé L'aptitude à empêcher la prise de nourriture de Melanotus communis Gyll. a été recherchée dans les extraits de 78 plantes appartenant à 24 familles. Cinq extraits de 4 familles ont réduit significativement les dégâts alimentaires lorsqu'il y avait choix alimentaire. Deux extraits — Asclepias tuberosa et Hedera helix — présentaient des niveaux exception-nellement élevés de dissuasion de l'alimentation. Une technique aux rayons X a montré que les taupins fouillaient indistinctement le sol contenant de ces extraits ou le sol avoisinant non traité, mais on les recontrait plus fréquemment dans le sol non traité.

     

斜纹夜蛾核型多角体病毒DNA诱导同源昆虫细胞的凋亡

发现野生型斜纹夜蛾核型多角体病毒（Spodoptera litura nuclear polyhedrosis virus,SpltNPV）DNA转染SL-1细胞能诱导细胞凋亡.SpltNPV-DNA转染其同源细胞系斜纹夜蛾核SL-1细胞6 h后,光镜下即可见细胞膜表面突出或形成小泡,细胞碎裂成凋亡小体,18 h后,细胞100%碎裂成凋亡小体.DAPI荧光染色显示感染细胞核渐呈半月形,直至碎裂被凋亡小体包裹.被转染的SL-1细胞DNA琼脂糖凝胶电泳呈典型梯形谱带.野生型SpltNPV病毒粒子感染的SL-1细胞既无多角体的出现,也无凋亡现象的发生.     

Insecticidal compound isolated from Syzygium lineare Wall. (Myrtaceae) against Spodoptera litura (Lepidoptera: Noctuidae)

A new crystal compound 2,5-diacetoxy-2-benzyl-4,4,6,6-tetramethyl-1,3-cyclohexanedione was isolated from the leaves of Syzygium lineare. The insecticidal activity of the compound was assessed against fourth instar larvae of Spodoptera litura. Its activity was better than the positive control azadirachtin. The compound was responsible for growth inhibition on S. litura. It induced larval, pupal and adult deformities even at low concentration. The compound may be useful as a botanical pesticide.     

斜纹夜蛾核多角体病毒抑制苜蓿丫纹夜蛾核多角体病毒诱导的斜纹夜蛾细胞凋亡

野生型苜蓿丫纹夜蛾核多角体病毒(Autographa californica multicapsid nucleopolyhedrovirus, AcMNPV)感染斜纹夜蛾(Spodoptera litura)细胞系Sl-zsu-1,可引起典型的细胞凋亡;但可以在草地夜蛾(Spodoptera frugiperda)细胞Sf-9中复制并形成多角体.比较了AcMNPV p35基因在病毒感染两种细胞的复制和转录情况,认为p35在非受纳细胞中及时有效的表达能阻止细胞发生凋亡;共感染实验结果表明,斜纹夜蛾核多角体病毒(Spodoptera litura multicapsid nucleopolyhedrovirus, SpltMNPV)可以抑制AcMNPV诱导的细胞凋亡并可帮助病毒进行复制,推测SpltMNPV基因组中与p35同源的p49基因挽救了细胞的自杀行为.     

Cross habituation to feeding deterrents and acceptance of a marginal host plant byPieris rapae larvae

Sensitivity of the cabbage butterfly,Pieris rapae L. to feeding deterrents was compared for larvae reared on different food sources under laboratory conditions. Since cabbage-reared larvae normally reject nasturtium,Tropaeolum majus L., the effects of previous exposure to allelochemicals on larval acceptance or rejection of this plant were also examined. When compared with cabbage-reared larvae, nasturtium-reared larvae were less sensitive to feeding deterrents including cymarin, erysimoside and 2-O-β-d-glucosyl cucurbitacin E. Nasturtium-reared larvae were insensitive to chlorogenic acid, which was deterrent to cabbage-reared larvae. Feeding by larvae reared on a wheat germ diet was not deterred by these compounds. The results indicate that dietary experience can extensively affect larval sensitivity to feeding deterrents and that cross habituation of larvae to deterrents occurs in response to certain chemical constituents of nasturtium and wheat germ diet. Digitoxin, however, proved to be an exception. Larvae reared on either nasturtium or wheat germ diet were as sensitive to digitoxin as those reared on cabbage. Previous results have shown that rejectionof nasturtium by cabbage-reared larvae is due to the presence of strong feeding deterrents in this plant. However, more than 50% of 2nd instar larvae reared from neonate on cabbage leaves treated with strophanthidin, cymarin, erysimoside, digitoxigenin and digitoxin accepted nasturtium as a food source. 2-O-β-d-glucosyl cucurbitacin E, 2-O-β-d-glucosyl cucurbitacin I and rutin were also active in causing larvae to feed on nasturtium. Thus dietary exposure to unrelated plant chemicals can profoundly affect insect acceptance of a plant that contains feeding deterrents.     

黄带犀猎蝽成虫对斜纹夜蛾幼虫的捕食功能反应

[目的] 探明黄带犀猎蝽成虫对斜纹夜蛾幼虫的捕食潜力。[方法] 在室内条件下,研究了黄带犀猎蝽对斜纹夜蛾2、3、4龄幼虫的捕食功能反应、搜寻效应和干扰反应。[结果] 黄带犀猎蝽成虫对斜纹夜蛾2、3、4龄幼虫的捕食功能反应模型均符合Holling II型,即其捕食量随猎物密度的增加而增加,其搜寻效应随猎物密度的增加而减小,HollingⅡ方程依次为：N_a=0.9750N/（1+0.0273N）、N_a=1.1654N/（1+0.0804N）,N_a=1.3058N/（1+0.1799N）;黄带犀猎蝽成虫自身密度干扰反应符合HasseⅡ型（E=0.337P^-0.565）,即随着自身密度的增加,平均捕食量逐渐减少,捕食作用率逐渐降低。[结论] 黄带犀猎蝽成虫对斜纹夜蛾幼虫有较好的防治潜力,可用于斜纹夜蛾的生物防治中。     

金龟子绿僵菌对斜纹夜蛾幼虫的生防效果、抗氧化酶活性和肠道细菌群落的影响

【目的】测定金龟子绿僵菌(Metarhizium anisopliae)对斜纹夜蛾(Spodoptera litura) 2龄幼虫的毒力,研究金龟子绿僵菌侵染后寄主体内抗氧化酶活性和肠道内细菌群落的变化,探讨斜纹夜蛾对金龟子绿僵菌侵染的防御机制。【方法】采用浸渍法测定不同浓度金龟子绿僵菌对斜纹夜蛾2龄幼虫的毒力;应用IlluminaMiSeq高通量测序技术测定肠道细菌群落。【结果】不同浓度的孢悬液对斜纹夜蛾2龄幼虫均有一定的毒力,处理7 d时半致死浓度(LC₅₀)为3.944 107个孢子/mL;浓度为1.0×10⁹个孢子/mL时,半致死时间最短(LT₅₀)为4.6 d,校正后的死亡率为81.03%。处理后未致死的斜纹夜蛾幼虫体内抗氧化酶活性显著高于对照组。处理后致死的斜纹夜蛾幼虫肠道细菌群落多样性显著高于对照组;且处理后致死的斜纹夜蛾幼虫肠道细菌群落组成与对照组差异显著。【结论】金龟子绿僵菌对斜纹夜蛾幼虫的致死率和致死效率与金龟子绿僵菌的浓度呈正相关;斜纹夜蛾幼虫体内的抗氧化酶可能在抵抗金龟子绿僵菌侵染的过程中起重要作...     

斜纹夜蛾核多角体病毒gp37及其邻近序列的克隆及分析

从斜纹夜蛾核多角体病毒(Spodoptera litura nucleopolyhedrovirus, SpltMNPV)基因组中克隆了gp37基因.分子生物学软件分析表明,在gp37基因内部存在糖基化位点.含有晚期表达基因的启动子序列(ATAAG),推测为晚期表达的病毒膜糖蛋白基因.通过GP37蛋白的同源性比较,绘制了以gp37基因为基础的杆状病毒进化树, 发现与以多角体蛋白基因（polyhedrin）为基础所绘制的杆状病毒分子进化树有较大差异.以polyhedrin基因为基础绘制的杆状病毒分子进化树将家蚕核多角体病毒（Bombyx mori nucleopolyhedrovirus, BmNPV）与杆状病毒代表种——苜蓿丫纹夜蛾核多角体病毒（Autographa californica multinucleocapsid nucleopolyhedrovirus, AcMNPV）分开,根据gp37基因分析则将二者归到同一分枝,这与以egt基因为基础绘制的杆状病毒分子进化树结果一致.     

Spontaneous plant regeneration in transformed roots and calli from Tylophora indica: changes in morphological phenotype and tylophorine accumulation associated with transformation by Agrobacterium rhizogenes

We examined the effects of genetic transformation by Agrobacterium rhizogenes on the production of tylophorine, a phenanthroindolizidine alkaloid, in the Indian medicinal plant, Tylophora indica. Transformed roots induced by the bacterium grew in axenic culture and produced shoots or embryogenic calli in the absence of hormone treatments. However, hormonal treatment was required to regenerate shoots in root explants of wild type control plants. Transformed plants showed morphological features typically seen in transgenic plants produced by A. rhizogenes, which include, short internodes, small and wrinkled leaves, more branches and numerous plagiotropic roots. Plants regenerated from transformed roots showed increased biomass accumulation (350–510% in the roots and 200–320% in the whole plants) and augmented tylophorine content (20–60%) in the shoots, resulting in a 160–280% increase in tylophorine production in different clones grown in vitro.     

甲维盐对斜纹夜蛾幼虫肠道细菌的影响

【目的】斜纹夜蛾幼虫属杂食性、高食量的害虫,通过分子生物学手段对经甲维盐处理后的斜纹夜蛾幼虫肠道微生物进行比对,研究肠道共生菌群受毒剂刺激后的代谢变化,探讨菌株的自身代谢与甲维盐的作用受体的相关性。【方法】基于Illumina MiSeq技术测序平台,对取食甲维盐和未取食甲维盐的斜纹夜蛾幼虫中肠细菌的16S rRNA可变区进行高通量测序,分析对比细菌群落结构多样性。【结果】肠杆菌属、根瘤菌属在斜纹夜蛾的肠道中占优势地位,经过甲维盐处理后两者的丰度大幅下降。沙雷氏菌属和黄单胞杆菌属在处理后减少到几乎为零,相反,原先不占据优势的棒状杆菌属和甲醇杆菌属,处理后丰度明显上升。【结论】甲维盐处理后的优势菌群以及丰富度均发生变化,表明斜纹夜蛾的肠道菌群结构可能与甲维盐毒理机制有关。     

药用植物千层塔的基原物种及研究进展

清代《植物名实图考》中记载的传统草药千层塔,之前被考证为石松科(Lycopodiaceae)石杉属(Huperzia Bernh)植物蛇足石杉(Huperzia serrata)。目前药学研究从中分离出的石杉碱甲,能够高效、高选择、可逆地抑制乙酰胆碱酯酶,减少乙酰胆碱分解,已广泛应用于改善记忆和治疗阿尔茨海默病,引起了世界的广泛关注。该文综述了国内外近40年来有关“蛇足石杉”在系统与分类学、遗传多样性、组学研究、内生真菌、化学成分、资源调查、栽培繁殖和资源保护等方面的研究进展,并从植物分类学研究角度出发,厘清原中国境内分布的蛇足石杉,实应为我国东北地区分布的Huperzia serrata和我国南方分布较广的H. javanica两个物种; 该研究结果显示,《植物名实图考》千层塔的基原,应是我国南方广布的石杉属植物H. javanica。考虑到药用植物和药材名称的稳定,将H. javanica的中文名沿用《植物名实图考》中的“千层塔”,H. serrata的中文名处理为“蛇足石杉”。     

响应面法优化爪哇虫草菌的培养条件及其对斜纹夜蛾的毒力和保护酶活性影响

【目的】优化爪哇虫草菌Bd01的固态发酵培养条件,测定分生孢子对斜纹夜蛾3龄幼虫的毒力,研究被爪哇虫草菌侵染后寄主体内的保护酶活性变化。【方法】采用单因素试验确定爪哇虫草菌Bd01最佳的固态培养基及培养条件,利用Box-Behnken响应面法优化发酵参数,采用浸渍法测定分生孢子对斜纹夜蛾3龄幼虫的毒力,同时利用分光光度计法测定斜纹夜蛾3龄幼虫体内酶活性变化。【结果】以产孢量为指标,通过响应曲面法优化的爪哇虫草菌Bd01最佳产孢条件为：培养基营养成分含量为30.24g/L,pH值为7.55,光照时长为12.06h,在该条件下,培养基的产孢量为2.78×10⁸孢子/mL。浓度为1×10⁸孢子/mL的爪哇虫草菌孢子液对斜纹夜蛾3龄幼虫具有一定毒力,处理7 d时致死中浓度(LT₅₀)为3.11 d,致死中时(LC₅₀)为4.68×10⁵孢子/mL,校正死亡率为88.68%。处理后未死亡的斜纹夜蛾幼虫体内保护酶活性与对照组相比发生显著变化。【结论】优化后的培养基能够显著增加爪哇虫草菌的产...     

Influence of incubation temperature on productivity and quality of Spodoptera litura nucleopolyhedrovirus

Mass production of baculoviruses by in vivo methods is influenced by several factors like larval age at virus treatment, virus concentration and the incubation temperature. The larval age at virus treatment and virus concentration should be synchronized to result in insect death at a fully grown larval stage to maximize the productivity. Since temperature influences both the growth of the larvae and replication of the virus, we evaluated the influence of incubation temperature on mass production of Spodoptera litura nucleopolyhedrovirus (SpltNPV) at four different temperature regimes viz., 25, 30, and 35 °C and room temperature by diet-surface contamination method. Incubation of early fifth instar larvae dosed with 3932.4 polyhedral inclusion bodies (PIB)/mm² at 25 °C enhanced the virus productivity to 6.623 × 10¹¹ PIB yield/100 inoculated larvae, while it was only 1.779 × 10¹¹ at 35 °C. The disease progression in the virus treated larvae was slow with median lethal time (LT₅₀) of 208 h at 25 °C as compared to 136 h at 35 °C. In spite of the slow death which means lower production cycles/year, the productivity/year was higher at 25 °C than at other temperatures. The SpltNPV produced at 25 °C was also found to be of superior quality in terms of low bacterial contaminants than at 35 °C. Neonate larval bioassay conducted with viruses produced at different temperature treatments revealed that they were similar in their activity and virulence. Hence our results indicate that maintenance of the SpltNPV production facility at 25 °C would enhance both the virus productivity and quality.     

Synthesis and evaluation of bioactive naphthoquinones from the Brazilian medicinal plant, Tabebuia avellanedae

A series of naphthoquinones based on the naphtho[2,3-b]furan-4,9-dione skeleton such as (−)-5-hydroxy-2-(1′-hydoxyethyl)naphtho[2,3-b]furan-4,9-dione (1) and its positional isomer, (−)-8-hydroxy-2-(1′-hydoxyethyl)naphtho[2,3-b]furan-4,9-dione (2), which are secondary metabolites found in the inner bark of Tabebuia avellanedae, were stereoselectively synthesized and their biological activities were evaluated in conjunction with those of their corresponding enantiomers. Compound 1 exhibited potent antiproliferative effect against several human tumor cell lines, but its effect against some human normal cell lines was much lower than that of mitomycin. On the other hand, its enantiomer (R)-1 was less active toward the above tumor cell lines than 1. The antiproliferative effect of 2 against all tumor cell lines was significantly reduced. These results indicated the presence of the phenolic hydroxy group at C-5 is of great important for increasing antiproliferative effect. In addition, 1 also showed higher cancer chemopreventive activity than 2, while there were no significant differences between 1 and 2 in antimicrobial activity. Both compounds displayed modest antifungal and antibacterial activity (Gram-positive bacteria), whereas they were inactive against Gram-negative bacteria.     

南方红豆杉内生及根际放线菌多样性及其生物活性

【目的】研究药用植物南方红豆杉内生及根际土壤放线菌的多样性及其抑菌、抗肿瘤等重要生物活性并获得一些具有强抑制植物病原真菌以及抗肿瘤等重要生物活性的菌株。【方法】选择7种培养基从南方红豆杉及其根际土壤中分离放线菌,对链霉菌进行形态学分类,去重复后对其进行抑制植物病原真菌以及抗肿瘤活性的筛选并对高活性菌株进行初步鉴定。对部分菌株进行16S rRNA基因测序分析研究其多样性。【结果】研究共分离得到277株放线菌,经去重复后剩余111株放线菌,可归类到6个亚目、7个科、8个属。其中链霉菌可分为10个类群。生物活性研究结果显示:30.9%的菌株具有抑制植物病原真菌活性,其中6株放线菌对多种植物病原真菌显示了强的抑菌活性。分别有44.1%和33.3%的菌株对胃癌肿瘤细胞株SGC-7901和肺癌肿瘤细胞株NCI-H460的抑制率在40%以上。【结论】药用植物南方红豆杉及其根际土壤蕴含种类丰富的放线菌资源,具有良好的生物学活性。菌株KLBMP 2170具有显著的抑菌以及抗肿瘤活性,值得我们去进一步研究。     

Corylomyces: a new genus of Sordariales from plant debris in France

The new genus Corylomyces, isolated from the surface of a hazelnut (Corylus avellana) in the French Pyrenees, is described, illustrated and compared with morphologically similar taxa. It is characterised by tomentose, ostiolate ascomata possessing long necks composed of erect to sinuose hairs, and one- or two-celled, opaque, lunate to reniform ascospores. Analyses of the SSU and LSU fragments rDNA gene sequences support its placement in the Lasiosphaeriaceae (Sordariales).     

Host plant derived feeding deterrence towards ants in the turnip sawfly Athalia rosae

Larvae of the sawfly Athalia rosae ruficornis Jakovlev (Hymenoptera: Tenthredinidae) feed on several glucosinolate-containing plants and have been shown to sequester the main glucosinolates of different hosts, namely sinalbin (p-hydroxybenzylglucosinolate) from Sinapis alba L., sinigrin (allylglucosinolate) from Brassica nigra (L.) Koch, and glucobarbarin ((S)-2-hydroxy-2-phenylethylglucosinolate) from Barbarea stricta Andrz. (Brassicaceae). These plant metabolites are stored in the haemolymph, which is readily released when larvae are attacked by predators. In a dual-choice bioassay the bio-activity of sawfly haemolymph collected from larvae reared on different host plants (S. alba, B. nigra, and B. stricta) was tested against the ant Myrmica rubra L. (Hymenoptera: Formicidae). The haemolymph had a stronger deterrence effect when the corresponding sawfly larvae were reared on S. alba than when reared on B. nigra and B. stricta. Haemolymph of caterpillars of Pieris rapae L. (Lepidoptera: Pieridae) that had fed on S. alba was not deterrent to the ants. No sinalbin could be detected in their haemolymph. The glucosinolates sinalbin and sinigrin, offered in a concentration comparable to that in the sawfly haemolymph, were deterrent to the ants, but not as strongly as the corresponding haemolymph samples. This suggests, that glucosinolates are not the only compounds involved in the chemical defence of A. rosae. However, the presence of sequestered glucosinolates is already a sufficient defence towards predators such as ants, and their effectiveness is modulated by the host plant chemistry.     

药用植物巴西吐根的引种繁殖及栽培初探

吐根作为治疗痢疾的特效药而著名,主要具有祛痰、催吐和抗阿米巴痢疾的作用。我国目前对吐根药材的需求全部依赖于进口,国内未有大规模种植,为此,该文对原产巴西的吐根进行了引种繁殖及栽培研究。结果表明:(1)云南省西双版纳傣族自治州景洪市的气候条件能满足吐根的正常生长发育的需求,可作为吐根的引种地。(2)吐根的分根和茎下段可用于扦插繁殖,其发根率和存活率分别100.0%和100.0%、68.0%和75.0%,前者优于后者。(3)用20 mg·L^-1的IAA或IBA浸泡1 h,吐根茎下段的扦插成活率为90.0%或88.0%,均显著高于对照,可用于提高吐根茎下段的扦插成活率。(4)采用分根繁殖的吐根植株在植株生长和药材外观性状较好,单株总根体积较高,吐根一年生植株平均株高为10.66 cm,两年生平均株高为16.54 cm,一年生植株根总体积为2.71 mL,两年生根总体积为3.54 mL。(5)吐根栽培基质可用腐殖土:椰糠体积比为4:1。(6)在吐根的年周期生长中,地径1—3月和9—11月增长明显,株高7—11月增长明显,叶片长和宽3—9月增长明显,根据这些特点,可科学制定相应的水肥管理措施。该研究结果可为吐根的引种繁殖和栽培提供一定的科学参考。