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31.
Ainara Pealver‐Cruz Elisa Garzo Ins Prieto‐Ruiz Miguel Díaz‐Carro Ana Winters Arnzazu Moreno Alberto Fereres 《Insect Science》2020,27(3):558-570
The continuous rise of CO2 concentrations in the atmosphere is reducing plant nutritional quality for herbivores and indirectly affects their performance. The whitefly (Bemisia tabaci, Gennadius) is a major worldwide pest of agricultural crops causing significant yield losses. This study investigated the plant‐mediated indirect effects of elevated CO2 on the feeding behavior and life history of B. tabaci Mediterranean species. Eggplants were grown under elevated and ambient CO2 concentrations for 3 weeks after which plants were either used to monitor the feeding behavior of whiteflies using the Electrical Penetration Graph technique or to examine fecundity and fertility of whiteflies. Plant leaf carbon, nitrogen, phenols and protein contents were also analyzed for each treatment. Bemisia tabaci feeding on plants exposed to elevated CO2 showed a longer phloem ingestion and greater fertility compared to those exposed to ambient CO2 suggesting that B. tabaci is capable of compensating for the plant nutritional deficit. Additionally, this study looked at the transmission of the virus Tomato yellow leaf curl virus (Begomovirus) by B. tabaci exposing source and receptor tomato plants to ambient or elevated CO2 levels before or after virus transmission tests. Results indicate that B. tabaci transmitted the virus at the same rate independent of the CO2 levels and plant treatment. Therefore, we conclude that B. tabaci Mediterranean species prevails over the difficulties that changes in CO2 concentrations may cause and it is predicted that under future climate change conditions, B. tabaci would continue to be considered a serious threat for agriculture worldwide. 相似文献
32.
Structural equation modelling reveals plant-community drivers of carbon storage in boreal forest ecosystems 总被引:1,自引:0,他引:1
Boreal forest ecosystems are important drivers of the global carbon (C) cycle by acting as both sinks and sources of atmospheric CO2. While several factors have been proposed as determining the ability of boreal forest to function as C sinks, little is known about their relative importance. In this study, we applied structural equation modelling to a previously published dataset involving 30 boreal-forested islands that vary greatly in their historic fire regime, in order to explore the simultaneous influence of several factors believed to be important in influencing above-ground, below-ground and total ecosystem C accumulation. We found that wildfire was a major driver of ecosystem C sequestration, and exerted direct effects on below-ground C storage (presumably through humus combustion) and indirect effects on both above-ground and below-ground C storage through altering plant-community composition. By contrast, plant diversity influenced only below-ground C storage (and even then only weakly), while net primary productivity and decomposition had no detectable effect. Our results suggest that while boreal forests have great potential for storing significant amounts of C, traits of dominant plant species that promote below-ground C accumulation and the absence of wildfire are the most important drivers of C sequestration in these ecosystems. 相似文献
33.
Eggs and rhabditiform juveniles of the ruminant parasite Trichostrongylus colubriformis developed normally in Caenorhabditis briggsae Maintenance Medium. A toxin from a crystal-enriched preparation of the bacterium Bacillus thuringiensis israelensis was lethal to nematode eggs and juveniles within 24 hours and to eggs and juveniles after 24 hours of development. Treated eggs had refractive granules and development was arrested, whereas nontreated eggs developed normally. Eggs treated after 24 hours of development contained juveniles that were granulated, had esophageal derangements, and were moribund or dead. The ovicidal toxin from B. t. israelensis may facilitate microbial control of parasitic nematodes. 相似文献
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The application of light reflectance for estimating biomass concentration was investigated on oxidative chemostat culture of Saccharomyces cerevisiae. A correlation between light reflectance and dry weight was established for biomass concentrations from 0.5 to 10 g l–1. The light reflectance signal was stable during the course of chemostat culture and proved to be sensitive to slight but fast changes in biomass concentration following shift-up in dilution rate, acetate pulse or during an oscillation. On-line estimated biomass revealed a larger time window of the biological response during spontaneous oscillations and could be used to predict carbohydrate storage. 相似文献
38.
Laboratory experiments and field measurements were conducted to examine the effect of tide on the organic carbon mineralization
rate in sediments under aerobic conditions of an intertidal estuary. Core samples of surface sediments were collected from
an intertidal estuary of the Kurose River, Hiroshima, Japan. To mimic low and high tide in the intertidal estuary, organic
carbon mineralization rates in the samples were measured in the laboratory under both air-exposed and submerged conditions.
Mineralization rates under air-exposed conditions were two to five times higher than those under submerged conditions. Field
measurements of the rate of CO2 emission from the sediment surface revealed a rapid increase in the rate as the sea level fell during ebb tide. The estimated
amount of daily organic carbon mineralization assuming a constantly submerged condition was 30% less than that estimated when
considering the semi-diurnal fluctuation in sea level. These results indicate that tide has a marked impact on the organic
carbon mineralization rate in sediments under aerobic conditions on an intertidal estuary, and tidal effects need to be considered
when the amount of mineralized organic carbon is estimated. 相似文献
39.
E. B. Kirichenko Yu. V. Orlova D. V. Kurilov 《Russian Journal of Plant Physiology》2008,55(6):846-853
Abstrac The composition of essential oil of Artemisia lerchiana Web. plants growing in Volgograd oblast was studied. Sampling was performed from plots contrasting in climatic and soil characteristics.
Essential oil was obtained by hydrodistillation. The content of essential oil in shoot biomass increased gradually during
shoot formation, flower bud formation, and flowering beginning and then decreased. The highest content of essential oil varied
from 1.1 to 1.5% of plant dry weight at the stage of flower bud formation. More than thirty compounds were identified by gas
chromatography-mass spectrometry. The following major components were found: camphor, borneol, bornylacetate, camphene, and
1,8-cineole. Some of compounds (sesquiterpenes and sesquiterpenoids) were identified for the first time. The time-course of
accumulation of essential oil components strongly depended on habitat edaphic factors and climatic conditions during the year
of sampling. The results permit a conclusion that A. lerchiana is a valuable producer of essential oils.
Original Russian Text ? E.B. Kirichenko, Yu.V. Orlova, D.V. Kurilov, 2008, published in Fiziologiya Rastenii, 2008, Vol. 55,
No. 6, pp. 934–941. 相似文献
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