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81.
The free-living nematodesPanagrellus redivivus andRhabditis oxycerca are strongly attracted to methyl, ethyl, propyl, butyl, and amyl acetate, to ethyl, propyl, and amyl formate and to ethyl propionate, but all the respective alcohols and acids are without effect. No loss of attraction is observed when the attractants are combined with lethal concentrations of the commercial nematicide sodium methyl dithiocarbamate. 相似文献
82.
Dichloromethane extracts of culture broth from three strains of the entomopathogenic fungusHirsutella thompsonii var.synnematosa were toxic to two species of tephritid fruit fly and inhibited conidial germination in vitro in several other entomopathogenic fungi includingBeauveria bassiana, Tolypocladium spp., andMetarhizium anisopliae. A major metabolite, toxic to apple maggot,Rhagoletis pomonella, and inhibitory to conidial germination inB. bassiana, was isolated and identified as the antibiotic (+)-phomalactone, 6-(1-propenyl)-5,-6-dihydro-5-hydroxypyran-2-one. This is the first biologically active compound of low molecular weight isolated from the genusHirsutella.Mention of a commercial or proprietary product does not constitute an endorsement by the USDA. 相似文献
83.
Greggory K. Storey Daniel J. Aneshansley Thomas Eisner 《Journal of chemical ecology》1991,17(4):687-693
Eggs ofUtetheisa ornatrix proved equally vulnerable to fungal infection (Beauveria bassiana, Paecilomyces lilacinus) whether they contained parentally provided pyrrolizidine alkaloid (monocrotaline) or were free of such alkaloid. In in vitro tests, monocrotaline, either as free base or N-oxide, had no inhibiting effect on fungal cultures.Report No. 99 of the series Defense Mechanisms of Arthropods; No. 98 is Attygalle et al.,Experientia (in press). 相似文献
84.
Catherine E. Airede Oladele F. Esuruoso 《Journal of the science of food and agriculture》1987,40(4):293-304
Autoclaved oil palm kernels were inoculated with spores of seedborne isolates of either Aspergillus flavus, A. niger, Penicillium chrysogenum, P. janthinellum, Paecilomyces varioti, Syncephalastrum racemosum or Fusarium oxysporum. At 0, 2, 4 and 8 weeks after inoculation, determinations were made of the moisture content, oil, free fatty acids (FFA), sugars and protein nitrogen. The principal biochemical changes induced by these fungi were increases in moisture content and FFA, decreases in total oil and total sugars and a degradation of protein nitrogen. Aspergillus flavus caused the greatest changes, and P. varioti caused the least changes under the moisture conditions of this experiment. The main type of deterioration was hydrolytic rancidity of the oil, resulting in a dark reddish-orange-coloured oil and a discoloration of the kernel meal. 相似文献
85.
将1份来自广东省韶关市仓储霉变稻米的稀释液接种至马铃薯葡萄糖琼脂(Potato Dextrose Agar,PDA)培养基上,利用平板划线法分离获得菌株,通过高效液相色谱-串联质谱对获得菌株的产柄曲霉素(Sterigmatocystin,STC)能力进行检测,结合形态学观察和rDNA-ITS序列分析对产毒素菌鉴定,并对其产STC菌株的产毒条件(培养基、培养天数、培养温度)进行考察。结果表明,该稻米中共分离到9种菌,其中Aspergillus jensenii可代谢合成STC,其最佳产毒培养基为大米培养基,最适温度为28℃,且在培养的第28天含量达到最大。该研究可为我国针对性的防控粮食中产毒性真菌污染提供基础性实验菌株,同时也有利于STC生物合成、代谢等工作的开展。 相似文献
86.
Xiaopeng Gao Fardausi Akhter Mario Tenuta Donald N Flaten Eugene J Gawalko Cynthia A Grant 《Journal of the science of food and agriculture》2010,90(5):750-758
BACKGROUND: A 3‐year field trial was conducted to investigate the effect of agricultural management practices including tillage, preceding crop and phosphate fertilization on root colonization by arbuscular mycorrhizal (AM) fungi and grain cadmium (Cd) concentration of durum wheat (Triticum turgidum L.). The relationship between grain Cd and soil and plant variables was explored to determine the primary factors affecting grain Cd concentration. RESULTS: Mycorrhizal colonization of the roots was reduced by conventional tillage or when the preceding crop was canola (Brassica napus L.), compared to minimum tillage or when the preceding crop was flax (Linum usitatissimum L.). In contrast, grain Cd was not consistently affected by any treatment. Grain Cd was generally below the maximum permissible concentration (MPC) of 100 µg Cd kg?1 proposed by WHO. Grain Cd varied substantially from year to year, and could be predicted with 70% of variance accounted for by using the model: grain Cd concentration = ? 321.9 + 44.5× ln(grain yield) + 0.26× soil DTPA‐Cd + 182.5× soil electrical conductivity (EC)? 0.98× grain Zn concentration. CONCLUSIONS: These common agricultural management practices had no effect on grain Cd concentration in durum wheat though they impacted mycorrhizal colonization of roots. Grain yield and to a lesser extent soil conditions of EC and DTPA‐Cd and grain Zn influenced grain Cd, whereas mycorrhizal colonization levels did not. Copyright © 2010 Crown in the right of Canada. Published by John Wiley & Sons, Ltd 相似文献
87.
Isabell Hildermann Monika Messmer David Dubois Thomas Boller Andres Wiemken Paul Mäder 《Journal of the science of food and agriculture》2010,90(12):2027-2038
BACKGROUND: For organic farming, cultivars are required with high nutrient use efficiency under nutrient limited conditions. Arbuscular mycorrhizal fungi (AMF) are known to contribute to nutrient uptake under low input conditions. We compared nutrient use efficiency (NUE) of old and modern organically and conventionally bred cultivars in organic and conventional systems and assessed AMF‐root colonisation (AMF‐RC) in relation to nutrient concentrations. RESULTS: Cultivars and systems had a statistically significant effect on nitrogen (N) and phosphorus (P) concentrations and NUE parameters, whereas no genotype × environment interactions appeared. In contrast to N and P uptake, the NUE parameters were higher under organic than under conventional conditions. NUE for N increased with the year of release of cultivars. In the organic systems, the organically bred cultivars could not outperform the conventionally bred cultivars in grain yield and NUE parameters. AMF‐RC was higher in the organic than in the conventional system, but did not differ among cultivars. CONCLUSION: Cultivars achieving high NUE in the organic systems were found among modern cultivars, irrespective of the breeding programme. Nutrient conditions during the breeding programme did not affect AMF‐RC. No clear evidence was found that AMF symbiosis contributed more to nutrient concentrations under low input than under high input conditions. Copyright © 2010 Society of Chemical Industry 相似文献
88.
89.
The objectives of this study were to determine the concentration of endotoxin, determine 20 water quality variables, and identify and enumerate fungal and bacterial pathogens from United States southern High Plains dairy lagoons and control lakes during summer and winter. Water samples were collected in triplicate from the north, south, east, and west quadrants of each body of water. The mean (± SEM) winter dairy lagoon endotoxin concentration was significantly higher (9,678 ± 1,834 ng/mL) than the summer concentration (3,220 ± 810 ng/mL). The mean endotoxin concentration of the 2 control lakes (summer: 58.1 ± 8.8 ng/mL; winter: 38.6 ± 4.2 ng/mL) was significantly less than that of the dairy lagoons. Two hundred-one Salmonella enterica spp. isolates were identified, 7 serovars were recovered from the dairy lagoons, and 259 Salmonella ssp. were identified from 5 other dairy locations (milk barn, ditch effluent, settling basin, feed alley pad flush, and center pivots). Twenty-eight Salmonella spp. were identified from center pivot water. Escherichia coli O157:H7 pathogens were isolated from other dairy locations but not from lagoons. Neither Salmonella spp. nor E. coli O157:H7 were identified from control lakes. Enterobacteriaceae opportunistic pathogens were isolated from both dairies and control lakes. Important mesophilic and thermophilic catabolic (to manure biosolids) fungal isolates were identified from dairy effluent locations, but no thermophilic fungal isolates were cultured from the control lakes. Adequate curing of green forage following center pivot irrigation is important to kill lagoon water enteric pathogens, even though the lagoon water is mixed with fresh water. Recirculating lagoon water to flush the feed alley pad, where cows stand while eating, to remove manure and using lagoon water to abate dairy dust in loafing pens and unimproved dairy roads is inconsistent with good environmental practice management. 相似文献
90.
Deteriorating effects of lichen and microbial colonization of carbonate building rocks in the Romanesque churches of Segovia, Spain 总被引:1,自引:0,他引:1
de Los Ríos A Cámara B García Del Cura MA Rico VJ Galván V Ascaso C 《The Science of the total environment》2009,407(3):1123-1134
In this study, the deterioration effects of lichens and other lithobionts in a temperate mesothermal climate were explored. We examined samples of dolostone and limestone rocks with visible signs of biodeterioration taken from the exterior wall surfaces of four Romanesque churches in Segovia (Spain): San Lorenzo, San Martín, San Millán and La Vera Cruz. Biofilms developing on the lithic substrate were analyzed by scanning electron microscopy. The most common lichen species found in the samples were recorded. Fungal cultures were then obtained from these carbonate rocks and characterized by sequencing Internal Transcribed Spacers (ITS). Through scanning electron microscopy in back-scattered electron mode, fungi (lichenized and non-lichenized) were observed as the most frequent microorganisms occurring at sites showing signs of biodeterioration. The colonization process was especially conditioned by the porosity characteristics of the stone used in these buildings. While in dolostones, microorganisms mainly occupied spaces comprising the rock's intercrystalline porosity, in bioclastic dolomitized limestones, fungal colonization seemed to be more associated with moldic porosity. Microbial biofilms make close contact with the substrate, and thus probably cause significant deterioration of the underlying materials. We describe the different processes of stone alteration induced by fungal colonization and discuss the implications of these processes for the design of treatments to prevent biodeterioration. 相似文献