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排序方式: 共有1771条查询结果,搜索用时 15 毫秒
1.
Relative growth rate correlates negatively with pathogen resistance in radish: the role of plant chemistry 总被引:2,自引:0,他引:2
E. HOFFLAND G. J. NIEMANN J. A. VAN PELT J. B. M. PUREVEEN G. B. EIJKEL J. J. BOON H. LAMBERS 《Plant, cell & environment》1996,19(11):1281-1290
Plant growth rate has frequently been associated with herbivore defence: a large investment in quantitative defence compounds occurs at the expense of growth. We tested whether such a relationship also holds for growth rate and pathogen resistance. For 15 radish (Raphanus sativus L.) cultivars, we determined the potential growth rate and the resistance to fungal wilt disease caused by Fusarium oxysporum. We subsequently aimed to explain a putative negative relationship between growth rate and resistance based on plant chemical composition. Both growth rate and resistance level varied greatly among cultivars. Moreover, there was a strong negative correlation between growth rate and resistance, i.e. there are costs associated with a high resistance level. Roots of slow-growing, resistant cultivars have a higher biomass density. Using pyrolysis mass spectrometry. we part1y explained variation in both growth rate and resistance in terms of the same change in chemical composition. Leaves of slow-growing, resistant cultivars contained more cell wall material. Surprisingly, roots of slow-growing, highly resistant cultivars contained significantly less cell wall material, and more cytoplasmic elements (proteins). We speculate that this higher protein concentration is related to high construction and turn-over costs and high metabolic activity. The latter in turn is thought to be responsible for a rapid and adequate resistance reaction, in which phenols may be involved. 相似文献
2.
Fusarium graminearum A 3/5 possesses a high affinity system (Km = 32 +/- 8 microM; mean +/- SE) for uptake of choline, which was shown to be energy-dependent and constitutive. The maximum rate of choline uptake by this system was repressed by ammonia and glucose, showing a three-fold increase in maximum activity after nitrogen (2 h) or carbon (4 h) starvation. The system was highly specific for choline with only dimethylethanolamine (Ki = 198 +/- 29 microM), betaine aldehyde (Ki = 95 +/- 14 microM) and chlorocholine (Ki = 352 +/- 40 microM) acting as competitive inhibitors. Hemicholinium-3 acted as a mixed (non-competitive) inhibitor (KIES = 1.9 +/- 0.6 microM; KIE = 3.6 +/- 1.9 microM). 相似文献
3.
4.
Samuel M. Imathiu Rumiana V. Ray Matthew I. Back Martin C. Hare Simon G. Edwards 《Journal of Phytopathology》2013,161(7-8):553-561
Fusarium langsethiae is a toxigenic fungal species that has been reported in European small‐grain cereal crops such as oats, wheat and barley. Although its relative contribution to fusarium head blight (FHB) symptoms is not well understood, it is reported to contaminate these cereals with high levels of HT‐2 and T‐2 trichothecenes mycotoxins that are currently under consideration for legislation by the European Commission. Ten commercial oat fields in Shropshire and Staffordshire (two adjacent counties in the Midlands) in the UK were surveyed in the 2006/2007 growing season. Samples were taken from predetermined field locations at Zadoks growth stages 32/33, 69, 77‐85 and 90‐92 for F. langsethiae biomass and HT‐2 and T‐2 toxins quantification. The results from this study showed that oats can be heavily infected with F. langsethiae and have high concentrations of HT‐2 and T‐2 toxins with no apparent FHB symptoms. The regression of HT‐2 + T‐2 toxins on F. langsethiae DNA concentration was highly significant (P < 0.001, r2 = 0.55). The results indicated that although F. langsethiae had no direct effect on crop yield, it may result in indirect economic losses where the grain can be rejected or downgraded as a result of intolerable levels of HT‐2 and T‐2 toxins, which are of human food and animal feed safety concern. The influence of cultural field practices on the infection and HT‐2 and T‐2 toxins accumulation in oats was not clear and warrants further studies to identify the sources of F. langsethiae inoculum and conditions favourable for infection and mycotoxin production. 相似文献
5.
Cynthia Nafula Wakhungu Isaiah Masinde Tabu O. Daniel Otaye Wafula Victor Wasike 《Archives Of Phytopathology And Plant Protection》2017,50(7-8):398-414
A study was carried out to determine Fusarium wilt distribution in Bambara nut farmers’ fields and its management using farm yard manure (FYM). Four villages in Busia County were purposively sampled for the study. The data generated were subjected to analysis of variance and treatment means separated by least significant difference test. Fusarium wilt incidence in the fields ranged from 14.63 to 43.56%. In the greenhouse, FYM reduced the disease incidence by 10.2% and severity by 9.5% on the black landrace and 1.9 and 12.8%, respectively, on the red landrace. In the field, FYM reduced disease incidence by 9.1% and severity by 6.9% on the black landrace and 10.4 and 10.4%, respectively, on the red landrace. Farm yard manure had the lowest area under disease progress curve irrespective of the landrace. The study confirmed the presence of the pathogen in the fields and the ability to manage the disease using FYM. 相似文献
6.
Summary
Fusarium oxysporum f. sp.dianthi, pathogenic on carnation plants is very sensitive toBacillus subtilis M51 inhibition.Fusarium oxysporum disease (fusariosis) is prevented for a period of two months after treatment of plants withBacillus subtilis M51. The persistence ofB. subtilis M51, marked for selenomycin resistance (MZ51) and inoculated on the roots of carnation cuttings was studied. Soil used was
two types: naturally infested withFusarium oxysporum and free from this pathogen. Bacterial cells presence on the roots was detected by direct plating and the presence of the
pathogen in the roots was investigated by histological assays. Evidence gathered by these procedures suggest that plant protection
is dependent on the physical presence ofB. subtilis M51 cells on the roots. 相似文献
7.
M. Buiatti C. Simeti S. Vannini G. Marcheschi A. Scala P. Bettini P. Bogani M. G. Pellegrini 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1987,75(1):37-40
Summary To obtain Tomato cell lines with an altered capacity to respond to heat-released cell wall components (elicitor) of a tomato pathogen (Fusarium oxysporum f. sp. lycopersici), positive and negative selection experiments, using BUdR enrichment techniques, were carried out on suspension cultures of the susceptible, low phytoalexin producer cultivar Red River. Both high and low phytoalexin producing clones were isolated. Further tests demonstrated that not all phytoalexin-producing clones were more susceptible to the elicitor toxic effect, and that they were altered also in the speed of response to fungal cell wall components. Cells selected with Fusarium elicitor showed the same behaviour when challenged by Phytophthora infestans elicitor, thus suggesting in this case lack of specificity. The results are finally discussed with a view to using the technique both as a tool to study the genetics and physiology of hostparasite interactions and as a possible new method for the selection of pathogen resistant genotypes.Paper no. 1224 IPRA-CNR; research supported by an EEC-BAP contract 相似文献
8.
A variety of interactions was recorded in culture between 11 saprobic fungi isolated from soybean (Glycine max) roots and seeds and the soybean pathogens Cercospora sojina, Colletotrichum truncatum, Macrophomina phaseolina, Phomopsis sojae, and Septoria glycines. The most active saprobes were Aspergillus terreus, Chaetomium cupreum, Epicoccum nigrum, Gliocladium roseum, Myrothecium roridum, Penicillium thomii, and Trichothecium roseum. Hyphal lysis of several fungal pathogens by Acremonium sp., C. cupreum and P. thomii was recorded perhaps because of parasitism by G. roseum and T. roseum. In greenhouse studies, seeds coated with G. roseum, P. thomii, and T. harzianum emerged significantly (P=0.05) more than those coated with A. terreus and the control. In field studies, seeds coated with a conidial suspension of A. terreus, G. roseum, P. thomii or Trichoderma harzianum produced a significantly greater stand than the control. The area of cotyledons covered with lesions caused by C. truncatum was significantly less on seeds coated with G. roseum, P. thomii and T. harzianum than the control. 相似文献
9.
Marc E. Savard J. David Miller Baharuddin Salleh Richard N. Strange 《Mycopathologia》1990,110(3):177-181
Extracts of rice on which an isolate of Fusarium chlamydosporum had been cultured were toxic to brine shrimps. The toxic fraction was purified by flash chromatography to give two compounds which were identified by UV, IR, NMR and mass spectroscopy at the 6 and 6 isomers of 5-hydroxy-4-methoxy-6, 8a-dimethyl-6,7-dihydro-2H,8aH-pyrano[2,3-b]pyran-2-one. These lactones for which the name chlamydosporol is proposed have not been reported previously. When tested in brine shrimp and HeLa cell assays, the LC50 concentration for a mixture of the isomers was approximately 400 g/ml in both systems. 相似文献
10.
Kenneth A. Voss Ronald D. Plattner Charles W. Bacon William P. Norred 《Mycopathologia》1990,112(2):81-92
Fusarium moniliforme has been associated with several diseases including equine leukoencephalomalacia, human esophageal cancer and hepatotoxicity/hepatocarcinogenicity in laboratory animals. The potential health risks to animals and humans posed by F. moniliforme contaminated grains cannot be assessed until the toxins are identified and toxicologically evaluated. As part of a systematic approach to identifying the hepatotoxins produced by F. moniliforme, diets containing aqueous and chloroform/methanol (11) extracts of F. moniliforme strain MRC 826 culture material (CM) and/or the extracted CM residues were fed to male Sprague-Dawley rats for four weeks. Serum alanine aminotransferase, aspartate aminotransferase and alkaline phosphatase activities were increased after two and four weeks and microscopic liver lesions were found in those animals fed aqueous CM extract and the CM residue after chloroform/ methanol extraction. Fumonisins B1 and B2 were extracted from the CM by water, but not chloroform/ methanol, and were present in the toxic diets at concentrations of 93–139 and 82–147 ppm, respectively. Nontoxic diets contained 22 ppm fumonisin B1 and 65 ppm fumonisin B2.Abbreviations CM
culture material
- ELEM
equine leukoencephalomalacia
Mention of a trademark, proprietory name or vendor does not imply its approval by the US Department of Agriculture to the exclusion of others that may also be suitable. 相似文献