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Ruurd de Jong Nevile Maher Bruno Patrian Erich St?dler Tammo Winkler 《Chemoecology》2000,10(4):205-209
Summary. Two recently identified compounds ("CIFs"), present on the leaf surface of Brassica oleracea (cabbage), are the strongest oviposition stimulants known for the cabbage root fly, Delia radicum. Cabbage leaves contain these compounds in extremely low concentrations, and the amount of CIFs obtained from purifying leaf
extracts was so small that it limited further research. We were able to purify far more of these two compounds from the roots
of Brassica napus var. napobrassica (rutabaga). Apart from being a richer source of CIFs, rutabaga roots are considerably easier to collect and process than
leaves. In addition, we isolated and identified a new CIF compound from the roots that is also very active in stimulating
oviposition in the cabbage root fly.
Received 26 May 2000; accepted 26 July 2000 相似文献
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Summary. Delia antiqua (Diptera: Anthomyiidae) females lay eggs between the leaves of onion plants or in the soil around the base of the plants,
then the maggots feed on the onion bulb and roots causing rapid secondary infection by fungi and bacteria. It is well known
that the first sensory modality used by the onion fly is vision, therefore the shape (vertical narrow cylinders) and colour
(yellow) of the plant play a crucial role in the recognition of a potential host plant. In the past it has been shown that
n-dipropyl disulfide (Pr2S2), a typical component of onion volatiles, is an important chemical host plant cue. We extracted host leaf surface to verify
if Pr2S2 is the major chemical oviposition stimulant and to determine if other as yet unknown substances may play a role in host-plant
selection. We confirmed that the females laid more eggs around onion plants with leaves than when only the onion bulb was
present and that the odour of chopped onion stimulates oviposition. Extraction of the surface of onion leaves revealed that
only the apolar fraction contained substances that stimulate egg-laying in D. antiqua. GC-EAD analysis indicated that a minor constituent, Pr2S2, is perceived by the olfactory receptor on the antennae of the onion fly females. This confirmed the importance of Pr2S2 as oviposition stimulant. Contact with the polar fraction did not stimulate egg-laying behaviour in this Delia species. We discuss the oviposition strategy of D. antiqua in comparison with its closely related species, D. radicum, in which the oviposition behaviour is stimulated mainly through contact with the cabbage leaf surface and only partially
by the host volatiles. 相似文献
269.
The platinum group elements (PGE) Pt, Pd and Rh are increasingly emitted into the environment by automobile catalytic converters. Whereas the biological availability of PGE to plants and animals has been demonstrated, only few studies concentrate on the influence of PGE on a cellular level. The effects of Pt, Pd and Rh compared with Cd, Ni and Cr on cell viability and oxidative stress response using soluble metal salts were studied in the human bronchial epithelial cell line BEAS-2B. Whilst Rh(III) showed little influence, both Pt(II) and Pt(IV) as well as Pd(II) had significant effects on cell viability at levels comparable to Cd(II) and Cr(VI). Arranging metal species in order of increasing toxicity as determined by LC50 yields: Rh(III)=1.2 mmol/L相似文献
270.
Conifer needles are used for the monitoring of atmospheric persistent organic pollutants. The objective of the present study was to develop a method for the detection of airborne chlorinated paraffins (CPs) using spruce needles as a passive sampler. The method is based on liquid extraction of the cuticular wax layer followed by chromatographic fractionation and detection of CPs using two different GCMS techniques. Total CP concentrations (sum of short (SCCP), medium (MCCP) and long chain CPs (LCCP)) were determined by EI-MS/MS. SCCP and MCCP levels as well as congener group patterns (n-alkane chain length, chlorine content) could be evaluated using ECNI-LRMS. For the first time, data on environmental airborne CPs on spruce needles taken within the Monitoring Network in the Alpine Region for Persistent and other Organic Pollutants (MONARPOP) are presented providing evidence that spruce needles are a suitable passive sampling system for the monitoring of atmospheric CPs. 相似文献