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1.
The need for environmentally friendly agricultural practices has led to the development of plant-based nematicides for root-knot nematode control. The efficacy of these botanicals has been tested primarily under laboratory and rarely under actual field conditions. Moreover, any side effects on non-target soil organisms that support soil biological activity are usually ignored. Herein, we evaluate the efficacy of Melia azedarach preparations against Meloidogyne spp. in a tomato greenhouse, by root gall examination and soil J2 enumeration. We also assessed side effects on soil microbes through PLFA analysis and microbivorous nematodes, and we quantified several plant growth parameters (e.g., fruit number and weight, root weight). Different treatments within the greenhouse included M. azedarach ripe fruit powder (MFP), ripe fruit water extract (MWE) and furfural, one of the principal active ingredients of M. azedarach and previously known to exhibit fumigant nematicidal activity. Results were compared to those obtained with the commercial nematicide oxamyl (Vydate® 10 SL) and an untreated control. All treatments were repeated every 20 days throughout the cultivation period. MFP and MWE suppressed Meloidogyne spp. often at the same levels obtained by furfural and oxamyl treatments and enhanced soil biological activity, as indicated by the proliferation of soil microbes and microbial feeding nematodes. Furfural and oxamyl adversely affected the soil community, especially the free-living nematodes. Moreover, furfural was phytotoxic to tomato plants in spite of its natural origin.  相似文献   
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Reserve networks are a major tool of ecological management aiming at biodiversity conservation. Maximizing the number of species conserved with the minimum land sacrifice is a primary requirement in reserve design. In this study, we examine the efficiency of five different scenarios to conserve: (i) the biodiversity of one target group and (ii) the overall biodiversity of an area. The study was conducted in Dadia Reserve, in northern Greece. Six groups of species were selected to represent its biodiversity: woody plants, orchids, Orthoptera, aquatic and terrestrial herpetofauna, and small terrestrial birds. The scenarios examined represent different conservation approaches to select network sites. For each approach, the starting point was one of the above six groups of species, considered as the target group. In scenario A, which reflects the hotspot approach, the sites richest in species are selected. Scenario B selects the sites most complementary in terms of species richness. The next two scenarios use the principle of environmental representativeness, expressed in terms of habitat (scenario C) or vegetation (scenario D). Under scenario E, sites forming the network are selected at random. The rank of scenarios in terms of preserving the species of the target group was always B > A > C > D > E, irrespective of the group considered as target group. Their rank, when preservation of the total biodiversity was the issue, was B, A > C, D > E.  相似文献   
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Chronic discharge of surplus organic matter is a typical side effect of fish aquaculture, occasionally leading to coastal eutrophication and excessive phytoplankton growth. Owing to their innate filter-feeding capacity, marine sponges could mitigate environmental impact under integrated multitrophic aquaculture (IMTA) scenarios. Herein, we investigated the clearance capacity of four ubiquitous Mediterranean sponges (Agelas oroides, Axinella cannabina, Chondrosia reniformis and Sarcotragus foetidus) against three microalgal substrates with different size/motility characteristics: the nanophytoplankton Nannochloropsis sp. (~3.2 μm, nonmotile) and Isochrysis sp. (~3.8 μm, motile), as well as the diatom Phaeodactylum tricornutum (~21.7 μm, nonmotile). In vitro cleaning experiments were conducted using sponge explants in 1 L of natural seawater and applying different microalgal cell concentrations under light/dark conditions. The investigated sponges exhibited a wide range of retention efficiencies for the different phytoplankton cells, with the lowest average values found for A. cannabina (37%) and the highest for A. oroides (70%). The latter could filter up to 14.1 mL seawater per hour and gram of sponge wet weight, by retaining 100% of Isochrysis at a density of 105 cells mL−1, under darkness. Our results highlight differences in filtering capacity among sponge species and preferences for microalgal substrates with distinct size and motility traits.  相似文献   
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The effect of essential oils and individual monoterpenoids on soil-borne fungi, in pure and mixed cultures, in growth media and in the soil environment, was investigated. Essential oils were extracted from lavender (Lavandula stoechas), oregano (Origanum vulgare subsp. hirtum), sage (Salvia fruticosa) and spearmint (Mentha spicata). The monoterpenoids tested were fenchone, carvacrol, 1,8-cineole, carvone, α-pinene and terpinen-4-ol. Their effect was examined on growth and sporulation of Aspergillus terreus, Fusarium oxysporum, Penicillium expansum and Verticillium dahliae isolated from an organic cultivation of tomato. All tested essential oils and individual monoterpenoids inhibited mycelial growth in all fungi and conidial production in most fungi. The strongest inhibitory activity on mycelial growth was exhibited by oregano and spearmint oils and by carvacrol and carvone, respectively their main constituents. The inhibitory activity was clearly fungistatic in A. terreus and F. oxysporum but fungicidal in V. dahliae. On sporulation, clearly stimulatory effects were observed alongside inhibitory ones. Conidial production was always promoted by α-pinene in P. expansum and by sage oil in F. oxysporum. At certain dosages it was promoted by cineole and carvone in F. oxysporum, and by lavender oil in A. terreus and V. dahliae. Experiments with carvone and carvacrol against mixed fungal cultures in a soil environment showed that V. dahliae was the most sensitive and A. terreus the most tolerant of the four fungi. Our results demonstrate strong but divergent effects and selectivity of action of the lower terpenoids on fungal strains that can become serious pests of tomato. Of special importance is the complete inhibition of growth and conidial production of V. dahliae, a pathogen otherwise very resistant to chemical control.  相似文献   
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Summary

During an ongoing effort to recover and preserve local germplasm, 14 accessions of indigenous minor grapevine (Vitis vinifera L.) cultivars from the Umbria Region, Central Italy, were chosen because they had been neglected and were threatened with extinction. Their phenotypic and genetic characteristics were evaluated through an ampelographic study of their shoots, mature leaves, bunches, and berries and by genomic analysis using an international set of nine microsatellite (simple sequence repeat; SSR) markers (VVS2, VVMD5, VVMD7, VVMD27, VrZAG62, VrZAG79, VVMD25, VVMD28, and VVMD32). Comparisons of the SSR profiles of all 14 accessions with grapevine accessions in several databases permitted the identification of unique genotypes, as well as possible synonyms. Information on these older, neglected cultivars will help to reduce the genetic erosion of grapevine germplasm, improve conservation and possible recovery, and assist in the future production of new, distinctive wines.  相似文献   
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BACKGROUND: The insecticides spinosad and deltamethrin are being increasingly used in pest management programmes. In order to assess further their toxic effects to target and non‐target insect species, an evaluation was made of their insecticidal profile on Bactrocera oleae (Rossi) and Drosophila melanogaster (Meig.). Moreover, possible genotoxic effects of the two pesticides were investigated using the somatic mutation and recombination test (SMART) in D. melanogaster. RESULTS: Both insecticides were highly effective against B. oleae, exhibiting similar LC50 values. Moreover, they were found to be more effective against Bactrocera than against Drosophila adults. However, spinosad was significantly more toxic than deltamethrin to D. melanogaster. The results showed a lack of genotoxic activity of both insecticides under the in vivo experimental procedure employed, at least at applied doses. CONCLUSION: The present study provides information for lethal and sublethal effects of spinosad and deltamethrin against a target and a non‐target species. Both insecticides can exert high toxicity to B. oleae when adults are exposed even to very low doses for long periods of time. The results contribute to the database on the genotoxic potential of spinosad and deltamethrin, suggesting a safety profile for both insecticides. Copyright © 2011 Society of Chemical Industry  相似文献   
9.
Sponges form symbiotic relationships with diverse and abundant microbial communities. Cyanobacteria are among the most important members of the microbial communities that are associated with sponges. Here, we performed a genus-wide comparative genomic analysis of the newly described marine benthic cyanobacterial genus Leptothoe (Synechococcales). We obtained draft genomes from Le. kymatousa TAU-MAC 1615 and Le. spongobia TAU-MAC 1115, isolated from marine sponges. We identified five additional Leptothoe genomes, host-associated or free-living, using a phylogenomic approach, and the comparison of all genomes showed that the sponge-associated strains display features of a symbiotic lifestyle. Le. kymatousa and Le. spongobia have undergone genome reduction; they harbored considerably fewer genes encoding for (i) cofactors, vitamins, prosthetic groups, pigments, proteins, and amino acid biosynthesis; (ii) DNA repair; (iii) antioxidant enzymes; and (iv) biosynthesis of capsular and extracellular polysaccharides. They have also lost several genes related to chemotaxis and motility. Eukaryotic-like proteins, such as ankyrin repeats, playing important roles in sponge-symbiont interactions, were identified in sponge-associated Leptothoe genomes. The sponge-associated Leptothoe stains harbored biosynthetic gene clusters encoding novel natural products despite genome reduction. Comparisons of the biosynthetic capacities of Leptothoe with chemically rich cyanobacteria revealed that Leptothoe is another promising marine cyanobacterium for the biosynthesis of novel natural products.  相似文献   
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Volatile oils from Thymus capitatus, Satureja thymbra and, to a lesser extent, Rosmarinus officinalis stimulate soil respiration. The S. thymbra oil is fungistatic to the germination of Penicillium citrinum spores in soil, and to mycelial growth of Mucor hiemalis in liquid culture. Addition of the S. thymbra oil and, to a lesser extent, R. officinalis oil to soil result in increased bacterial numbers. Bacteria appear to use the oils as carbon and energy sources. Thus the oils appear to have an ecological effect by shifting the soil population balance from fungi to bacteria.  相似文献   
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