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侧沟茧蜂触角感觉器的扫描电镜观察 总被引:11,自引:0,他引:11
扫描电镜观察表明:侧沟茧蜂Microplitis sp.的触角上存在5种感觉器,分别为毛状感觉器A型、B型、C型,槽状感觉器,锥形乳头状感觉器,刺形感觉器和钟形感觉器。对触角感觉器的形态和分布进行了描述,并对两性间的差别进行了讨论,为研究该蜂寻找生境和寄生行为提供依据。 相似文献
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Nataa Mehle Maja Kova
Nataa Petrovi
Marua Pompe Novak pela Baebler Hana Kre
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Stres Kristina Gruden Maja Ravnikar 《Physiological and Molecular Plant Pathology》2004,64(6):19
The aim of this work was to correlate the appearance of the symptoms, multiplication and spread of virus after mechanical inoculation of potato (Solanum tuberosum L.) cultivars showing different levels of susceptibility and sensitivity to Potato virus YNTN (PVYNTN). The potato cultivars used were the resistant cultivar Sante and susceptible cultivars Igor, Pentland squire and Désirée. The spread of the virus PVYNTN in infected plants was monitored using different methods: DAS-ELISA, tissue printing, immuno-serological electron microscopy and real-time PCR. In all three susceptible cultivars, the virus was detected in the inoculated leaves 4–5 days after inoculation. From there virus spread rapidly, first into the stem, then more or less simultaneously to the upper leaves and roots. Real-time PCR was shown to be very sensitive and enabled viral RNA to be detected in non-inoculated leaves of susceptible cultivar Igor earlier than other methods. Therefore, for exact studies of plant–virus interaction, a combination of methods which detect viruses on the basis of their different properties (coat protein, morphology or RNA) should be used to monitor the spread of viruses. 相似文献
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Dawn E. Hall Kennaway B. MacGregor Jaap Nijsse Alan W. Bown 《European journal of plant pathology / European Foundation for Plant Pathology》2004,110(4):441-447
Plant resistance to insect herbivory involves gene expression in response to wounding and the detection of insect elicitors in oral secretions (Kessler and Baldwin, 2002, Ann. Rev. Plant/ Biol. 53: 299–328). However, crawling insect larvae stimulate the synthesis of 4-aminobutyrate within minutes and imprints of larval footsteps can be visualized within seconds through superoxide production or transient increases in chlorophyll fluorescence (Bown et al., 2002, Plant Physiol. 129: 1430–1434). Here cryo-scanning electron microscopy was used to demonstrate that larval feet, which are equipped with a perimeter row of hook-like crochets, damage leaf tissue and result in larval footprints. Staining for cell death shows that areas of wounding correspond to footsteps detected through increased chlorophyll fluorescence. Superoxide production in response to footsteps was inhibited by diphenyleneiodonium, an inhibitor of the plasma membrane NADPH oxidase enzyme. Inhibition of superoxide production, however, did not eliminate the detection of cell death. The results demonstrate that larval footsteps damage leaf tissue, and initiate rapid local responses which are not dependent on herbivory or oral secretions. It is proposed that superoxide production at the wound site prevents opportunistic pathogen infection. 相似文献
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Estimating future fluxes of CH4 between land and atmosphere requires well-conceived process-based biogeochemical models. Current models do not represent the anaerobic oxidation of methane (AOM) in land surface soils, in spite of increasing evidence that this process is widespread. Our objective was to determine whether AOM, or potential AOM, commonly occurs in 20 hydromorphic soils spanning a wide range of chemical properties. Bulk soil samples were collected under shallow water near the shoreline of 15 recently drained fish ponds in southern Bohemia (Czech Republic), as well as from below the water table at 3 peatland locations in northeast Scotland and 2 acid sulfate soils on the southern coast of Finland. Each soil slurry was incubated under both oxic and anoxic conditions, with or without the addition of alternative electron acceptors (SO42− and NO3−) or H2PO4−. Here, “oxic” and “anoxic” conditions refer to anoxic soil respectively incubated in a headspace containing air or argon. Using the isotope dilution method, we determined the gross production and oxidation rates of CH4 after 2 days incubation under oxic headspace conditions, and after 2, 21 and 60 days incubation under anoxic conditions. Large differences in net CH4 fluxes were observed between soil types and between incubation conditions. AOM was detected in each of the 20 bulk soil samples, which spanned >6 pH units and 2 orders of magnitude in organic C content. Significant positive relationships were found between AOM and gross CH4 production rates under anoxic conditions, resulting in AOM rates that were sometimes higher than CH4 oxidation rates under oxic headspace conditions. There was no relationship between net and gross CH4 production rates, such that 2 soil types could display similar low net rates, yet conceal very large differences in gross rates. The effects of alternative electron acceptors on AOM were idiosyncratic and resulted in no net trend. We did find, however, a negative effect of SO42− and H2PO4− on gross CH4 production rates under anoxic and oxic conditions respectively. Under oxic headspace conditions, CH4 oxidation was related to soil organic C content. Taken collectively, our results suggest that AOM, or potential AOM, is prevalent over a wide range of soil types, that AOM may contribute substantially to CH4 oxidation in soils, and that AOM in soils should be integrated to current process-based CH4 cycling models. 相似文献
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为比较几种固定条件对不同植物材料样品电镜超微结构图像清晰度的影响。以3个不同科属4种植物[油棕(Elaeis gineansis Jacq.)、拟南芥(Arabidopsis thaliana.)、花生(Arachis hypogaea Linn.)、柱花草(Stylosanthes guianensias Sw.)]为研究主体代表,探讨了2.5%戊二醛与4%戊二醛固定过夜、锇酸固定2 h及过夜的制备方法对其叶片超微结构的影响,并成功观察了柱花草接种胶苞炭疽野生型菌株CH008后的病菌侵入过程。结果表明:油棕、拟南芥、花生及柱花草叶片经4%戊二醛与1%锇酸固定液固定过夜,其组织成像的效果均较为理想,各种细胞器整体信息丰富、结构组织完好、线条清晰。表明,此制备方法能够较好的保存植物叶片和细胞组织,提高制样的成功率及观察分辨率。 相似文献
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