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981.
Episyrphus balteatus DeGeer (Diptera, Syrphidae) is an abundant and efficient aphid-specific predator. We tested the electroantennographic (EAG)
response of this syrphid fly to the common aphid alarm pheromone, (E)-β-farnesene (EβF), and to several plant volatiles, including
terpenoids (mono- and sesquiterpenes) and green leaf volatiles (C6 and C9 alcohols and aldehydes). Monoterpenes evoked significant
EAG responses, whereas sesquiterpenes were inactive, except for the aphid alarm pheromone (EβF). The most pronounced antennal
responses were elicited by six and nine carbon green leaf alcohols and aldehydes [i.e., (Z)-3-hexenol, (E)-2-hexenol, (E)-2-hexenal, and hexanal]. To investigate the behavioral activity of some of these EAG-active compounds, E. balteatus females were exposed to R-(+)-limonene (monoterpene), (Z)-3-hexenol (green leaf alcohol), and EβF (sesquiterpene, common aphid alarm pheromone). A single E. balteatus gravid female was exposed for 10 min to an aphid-free Vicia faba plant that was co-located with a semiochemical dispenser. Without additional semiochemical, hoverfly females were not attracted
to this plant, and no oviposition was observed. The monoterpene R-(+)-limonene did not affect the females’ foraging behavior, whereas (Z)-3-hexenol and EβF increased the time of flight and acceptance of the host plant. Moreover, these two chemicals induced oviposition
on aphid-free plants, suggesting that selection of the oviposition site by predatory hoverflies relies on the perception of
a volatile blend composed of prey pheromone and typical plant green leaf volatiles. 相似文献
982.
Gibb AR Suckling DM Fielder S Bunn B Jamieson LE Larsen ML Walter GH Kriticos DJ 《Journal of chemical ecology》2008,34(9):1125-1133
Two sex pheromone components of the gum leaf skeletonizer, Uraba lugens (Lepidoptera: Nolidae), recently established in New Zealand, were identified. Gas chromatography (GC) electroantennographic detection analyses of female pheromone gland extracts gave three compounds that consistently elicited antennal responses. Chemical analyses, using GC and GC-mass spectrometry, in conjunction with 4-methyl-1,2,4-triazoline-3,5-dione and dimethyldisulfide derivatizations, identified these compounds as (10E,12Z)-hexadecadien-1-yl acetate (E10,Z12-16:Ac), (10E,12Z)-hexadecadien-1-ol (E10,Z12-16:OH), and (Z)-11-hexadecen-1-yl acetate (Z11-16:Ac). A trapping trial in Queensland, Australia, in 2002, indicated that a blend of the two major components E10,Z12-16:Ac and E10,Z12-16:OH could attract gum leaf skeletonizer males. In the same trial, E10,Z12-16:Ac alone trapped large numbers of an unidentified nolid, Nola spp. Further trials in Auckland, New Zealand established that these two components were sufficient and necessary for trap catch of males; adding minor gland components, (10E,12E)-hexadecadien-1-yl acetate (E10,E12-16:Ac), Z11-16:Ac, or octadecan-1-ol (18:OH), to the two-component lure did not result in increased trap catches. Behavioral observations and gland analyses of the Auckland population revealed that female moths begin calling soon after emergence, with peak calling and pheromone production occurring 7 hr into the scotophase. Analysis of gland extract at two-hourly intervals during the first activity period showed that the ratio of E10,Z12-16:Ac to E10,Z12-16:OH (mean of 86: 14, respectively) and pheromone titer were fairly constant. No qualitative or quantitative differences in pheromone components were detected between gland extracts from Tasmanian univoltine and Auckland bivoltine populations of U. lugens. 相似文献
983.
Oolong tea and LR‐White resin: a new method of plant sample preparation for transmission electron microscopy
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Simplifying sample processing, shortening the sample preparation time, and adjusting procedures to suitable for new health and safety regulations, these issues are the current challenges which electron microscopic examinations need to face. In order to resolve these problems, new plant tissue sample processing protocols for transmission electron microscopy should be developed. In the present study, we chose the LR‐White resin‐assisted processing protocol for the ultrastructural observation of different types of plant tissues. Moreover, we explored Oolong tea extract (OTE) as a substitute for UA in staining ultrathin sections of plant samples. The results revealed that there was no significant difference between the OTE double staining method and the traditional double staining method. Furthermore, in some organelles, such as mitochondria in root cells of tomatoes and chloroplast in leaf cells of watermelons, the OTE double staining method achieved little better results than the traditional double staining method. Therefore, OTE demonstrated good potentials in replacing UA as a counterstain on ultrathin sections. In addition, sample preparation time was significantly shortened and simplified using LR‐White resin. This novel protocol reduced the time for preparing plant samples, and hazardous reagents in traditional method (acetone and UA) were also replaced by less toxic ones (ethanol and OTE). 相似文献
984.
985.
烟青虫和棉铃虫在陕西烟区的地理分布及其成因分析 总被引:4,自引:1,他引:4
调查表明,烟青虫Helicoverpaassulta(Guenee)在陕西仅分布于关中和陕南;棉铃虫Helicoverpaarmigera(Hubner)虽在陕西各地烟田均有发生,但主要分布于陕北和关中。从地理上看,棉铃虫在陕北延安等地严重危害烤烟;在关中则主要危害烤烟留种田和晒烟留种株;在陕南发生极少,仅开花后在花上有少量幼虫。从生育期上看,在两种害虫混发的关中地区,团棵至旺长期主要是烟青虫,而棉铃虫仅在干旱的渭北旱塬上发生,开花后则逐渐过渡到棉铃虫为主,9月以后留种田发生的全为棉铃虫。推测棉铃虫起源于北方干旱地区,烟青虫则起源于湿润的东洋区。讨论了这两种夜蛾分布区差异以及造成中关烟田早、中晚期区系组成差异的原因。初步提出了烟青虫和棉铃虫在陕西当地蜜源植物间转移的可能规律.并提出了防治对策的建议。 相似文献
986.
987.
The genus Iris L., comprising approximately 210 species, is one of the most species-rich genera in the family Iridaceae. In this study, the first comprehensive leaf micromorphological characters of Korean irises were studied using light and scanning electron microscopy. Our objective was to evaluate the foliar micromorphological characteristics (namely epidermal cells, stomata types, and guard cell size) of Korean Iris taxa in a systematic context. All the investigated Korean Iris taxa had amphistomatic or hypostomatic leaves with anomocytic stomatal complexes. Guard cell length varied among species, ranging from 24.8 μm (I. rossii) to 56.0 μm (I. domestica). Although the presence of papillae on the outer periclinal wall is not of taxonomic significance, leaf margin pattern, guard cell size, and sunken stomata type were useful for species-level identification of Korean Iris species. The occurrence of polymorphic stomatal types was reported here for the first time, and the correlation between genome size and epidermal guard cell length was discussed. 相似文献
988.
989.
Lucèia Fàtima Souza Lucia Caputo Ingrid Bergman Inchausti De Barros Florinda Fratianni Filomena Nazzaro Vincenzo De Feo 《International journal of molecular sciences》2016,17(9)
The aims of this work were to study the chemical composition of the essential oil from the leaves of Pereskia aculeata and to evaluate some biological activities of three leaf extracts. The phenolic content, antioxidant activity, and in vitro antimicrobial and antifungal activities were determined. The methanol extract showed antioxidant activity (EC50 7.09 mg/mL) and high polyphenols content (15.04 ± 0.31 mg gallic acid equivalents (GAE)/g). The petroleum ether extract exhibited potent antibacterial activity against Escherichia coli, whereas the chloroform extract showed inhibitory activity against Bacillus cereus and Staphylococcus aureus. The petroleum ether and methanol extracts were more effective in inhibiting the growth of Aspergillus versicolor. The possible cytotoxicity of extracts on neuroblastoma SH-SY5Y cancer cell line and the influence on adenylate cyclase (ADCY) expression was also studied. P. aculeata chloroform extract showed antiproliferative activity with an IC50 value of 262.83 µg/mL. Treatments of SH-SY5Y neuroblastoma cells with 100 µg/mL of methanol extract significantly reduced ADCY1 expression. 相似文献
990.