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Wahida Loucif-Ayad Azzedine Chefrour Moath Algharibeh Nizar Haddad 《Phytoparasitica》2013,41(4):445-447
Deformed wing virus (DWV) is reported for the first time in honeybee colonies in Algeria. 相似文献
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Effects of shifting cultivation on biological and biochemical characteristics of soil microorganisms in Khagrachari hill district,Bangladesh 总被引：1，自引：0，他引：1
We collected soil samples from two representative sites at Aatmile of Khagarachari hill district in Chittagong Hill Tracts. One of the sites was under shifting cultivation and the other an adjacent 13-year old teak plantation. Both sites were in the same physiographic condition and same aspect with parable soil type, which enabled us to measure the effects of shifting cultivation on soil micro-flora. We studied soil physico-chemical properties and the biochemical and biological properties of soil microbes. Moisture and organic matter content as well as fungi and bacterial populations, both in surface and subsurface soils, were significantly(p ≤0.001) lower in shifting cultivated soils compared to soils not under shifting cultivation, i.e. the teak plantation site. The most abundant bacteria in surface(0-10 cm) and sub-surface(10-20 cm) soils under shifting cultivation were Pseudomonas diminuta and Shigella, respectively, while in corresponding soil layers of teak plantation, predominant microbes were Bacillus firmus(0-10 cm) and Xanthomonas(10-20 cm). The microbial population differences cannot be explained by soil texture differences because of the textural similarity in soils from the two sites but could be related to the significantly lower moisture and organic matter contents in soils under shifting cultivation. 相似文献
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Wahida Salma Reidar Myklebust Terry M Mayhew Einar Ringø 《Aquaculture Research》2011,42(12):1830-1839
The present investigation addresses whether the midgut (MG) of Atlantic cod (Gadus morhua L.) is an infection route for Vibrio (Listonella) anguillarum serotype 02 β and if Carnobacterium maltaromaticum, a probiotic bacterium, can out‐compete the pathogen and modulate the autochthonous MG microbiota. This was investigated by using an ex vivo method the intestinal sac, utilized previously in studies on Atlantic cod and Atlantic salmon (Salmo salar L.). Exposure of the MG to V. (L.) anguillarum did not reveal any cell damage indicating that the MG does not appear to be an infection route for V. (L.) anguillarum in healthy Atlantic cod. This finding together with previous observations on Atlantic cod and Atlantic salmon indicate that intestine as an infection route might vary between these two species. When the MG was exposed to C. maltaromaticum, no cell damage or cellular disruptions were observed. As budding from the apices of microvilli was observed in all treatments exposed to bacteria, we suggest that budding might be involved in the primary barrier against bacterial infection. However, to clarify this hypothesis, further studies are needed. Exposure of the MG to the probiotics and pathogenic bacteria indicated that C. maltaromaticum, to some extent, is able to out‐compete V. (L.) anguillarum but the topic merits further investigation. Analysis of the MG microbiota after sterile saline solution and bacterial exposure indicates that bacteria related to Staphylococcus sciuri belong to the autochthonous gut microbiota in Atlantic cod. 相似文献
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Maestre FT Quero JL Gotelli NJ Escudero A Ochoa V Delgado-Baquerizo M García-Gómez M Bowker MA Soliveres S Escolar C García-Palacios P Berdugo M Valencia E Gozalo B Gallardo A Aguilera L Arredondo T Blones J Boeken B Bran D Conceição AA Cabrera O Chaieb M Derak M Eldridge DJ Espinosa CI Florentino A Gaitán J Gatica MG Ghiloufi W Gómez-González S Gutiérrez JR Hernández RM Huang X Huber-Sannwald E Jankju M Miriti M Monerris J Mau RL Morici E Naseri K Ospina A Polo V Prina A Pucheta E 《Science (New York, N.Y.)》2012,335(6065):214-218
Experiments suggest that biodiversity enhances the ability of ecosystems to maintain multiple functions, such as carbon storage, productivity, and the buildup of nutrient pools (multifunctionality). However, the relationship between biodiversity and multifunctionality has never been assessed globally in natural ecosystems. We report here on a global empirical study relating plant species richness and abiotic factors to multifunctionality in drylands, which collectively cover 41% of Earth's land surface and support over 38% of the human population. Multifunctionality was positively and significantly related to species richness. The best-fitting models accounted for over 55% of the variation in multifunctionality and always included species richness as a predictor variable. Our results suggest that the preservation of plant biodiversity is crucial to buffer negative effects of climate change and desertification in drylands. 相似文献
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