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排序方式: 共有163条查询结果,搜索用时 15 毫秒
71.
Nora Scarcelli Serge Tostain Cédric Mariac Clément Agbangla Ogoubi Da Julien Berthaud Jean-Louis Pham 《Genetic Resources and Crop Evolution》2006,53(1):121-130
‘Domestication’ is a traditional farmers’ practice reported for yams (Dioscorea sp.) in Benin (West Africa). It involves introducing ‘spontaneous’ (naturally occurring) yams, supposedly wild (D. abyssinica and D. praehensilis), in varieties of the D. cayenensis–D. rotundata cultivated species complex. In this study, we established the genetic nature of ‘predomesticated’ yam plants using the amplified
fragment length polymorphism (AFLP) technique. A total of 213 accessions, consisting of 32 predomesticated yams, 70 D. cayenensis–D. rotundata, 86 D. abyssinica and 25 D. praehensilis yams were analysed. Using 91 AFLP markers, three groups of accessions were distinguished, broadly corresponding to the above
botanical species. Of the 32 predomesticated accessions, 16% were clustered with D. praehensilis, 37% with D. abyssinica and the remaining 47% with D. cayenensis–D. rotundata. These results demonstrated the use of wild plants by farmers in their domestication process, and suggested that plants derived
from intervarietal and interspecific hybridisation may also be subject to this process. This study has shown that through
domestication farmers influence and increase the genetic diversity in yam by using sexual reproduction of wild and possibly
cultivated yams. 相似文献
72.
Fiorucci S Golebiowski J Cabrol-Bass D Antonczak S 《Journal of agricultural and food chemistry》2007,55(3):903-911
Quercetin, one of the most representative flavonoid compounds, is involved in antiradical, antioxidant, and prooxidant biological processes. Despite a constant increase of knowledge on both positive and negative activities of quercetin, it is unclear which activated form (quinone, semiquinone, or deprotonated) actually plays a role in each of these processes. Structural, electronic, and energetic characteristics of quercetin, as well as the influence of a copper ion on all of these parameters, are studied by means of quantum chemical electronic structure calculations. Introduction of thermodynamic cycles together with the role of coreactive compounds, such as reactive oxygen species, gives a glimpse of the most probable reaction schemes. Such a theoretical approach provides another hint to clarify which reaction is likely to occur within the broad range of quercetin biological activities. 相似文献
73.
Sylvie Augustin Neil Boonham Willem J. De Kogel Pierre Donner Massimo Faccoli David C. Lees Lorenzo Marini Nicola Mori Edoardo Petrucco Toffolo Serge Quilici Alain Roques Annie Yart Andrea Battisti 《EPPO Bulletin》2012,42(3):515-551
This paper provides reviews of the most commonly used methods to detect plant pests belonging to groups of invasive organisms with high economic relevance, including Coleoptera (bark beetles, flathead borers, leaf beetles, longhorn beetles, weevils), Diptera (cone and seed flies, fruit flies), Homoptera (aphids, leafhoppers and psyllids, whiteflies), Lepidoptera (moths and butterflies), Thysanoptera (thrips), bacteria (potato brown rot Ralstonia solanacearum) and fungi (pitch canker disease Gibberella circinata, brown rot disease Monilinia fructicola). Future perspectives in detection methods are discussed, with particular reference to the considerable increase in the volume, commodity type and origins of trade in plant material from third countries, the introduction of new crops, the continuous expansion of the EU with new border countries being added, and the impact of climate change affecting the geographical boundaries of pests and their vectors. 相似文献
74.
75.
Determination of poly(ethylene glycol)-binding to browse foliage, as an assay of tannin, by near-infrared reflectance spectroscopy 总被引:1,自引:0,他引:1
Landau S Dvash L Decandia M Cabiddu A Shapiro F Molle G Silanikove N 《Journal of agricultural and food chemistry》2004,52(3):638-642
Nutritionists are interested in functional assays of tannins that do not require time-consuming and expensive extraction, such as the (14)C-labeled poly(ethylene glycol) (PEG)-binding (PEG-b) assay. This paper reports the application of near-infrared (NIR) spectroscopy to determine the percentage of PEG binding, in place of the (14)C-labeled PEG-b assay of tannin, in Mediterranean woodland vegetation. Calibration was done with 53 samples from 14 species and was validated on 25 samples from 10 species. PEG-b ranged between 1.4 and 20.7% in the samples. The calibration obtained by using the modified partial least-squares (MPLS) method, with all wavelengths in the 1100-2500 nm range combined, and the validation were reasonably linear (R (2) = 0.96 and 0.91, respectively). The accuracies, estimated from the standard errors of cross-validation and prediction, were +/-1.6 and +/-1.7% PEG-b, respectively. The NIRS-aided procedure proposed here can serve as an accurate, inexpensive, time-saving, and environment-friendly functional assay of tannin in Mediterranean browse. 相似文献
76.
Authentication of the origin of vanillin using quantitative natural abundance 13C NMR 总被引:2,自引:0,他引:2
Tenailleau EJ Lancelin P Robins RJ Akoka S 《Journal of agricultural and food chemistry》2004,52(26):7782-7787
The use of 13C isotopic distribution as an efficient means to determine the origin of vanillin has been substantiated. Using quantitative 13C NMR, the 13C/12C ratios at all eight carbon positions can be exploited. On a set of 21 samples of vanillin from five different origins, complete discrimination can be achieved. It is shown that, for many purposes, a rapid analysis in which only five sites are used is sufficient. However, improved discrimination using all eight sites is preferable to differentiate between different methods of production from natural ferulic acid or between natural and lignin-derived vanillin on the basis of the 13C/12C ratios characteristic of different origins. The C1 and C8 positions are demonstrated to be the most significant sites for discrimination using principle component analysis. However, aromatic carbon positions make an essential contribution, notably in differentiating between natural and lignin-derived vanillin. 相似文献
77.
Sage L Krivobok S Delbos E Seigle-Murandi F Creppy EE 《Journal of agricultural and food chemistry》2002,50(5):1306-1311
Eleven samples of grapes and musts used in red table wines were investigated for the occurrence of potential ochratoxin A (OTA)-producing molds. From these samples, 59 filamentous fungi and 2 yeasts were isolated. Among the 30 genera isolated, Deuteromycetes were the most frequent (70%) followed by Ascomycetes (10%). Six of the eleven grapes samples were contaminated by potentially ochratoxinogenic strains (Penicillium chrysogenum and Aspergillus carbonarius). When cultivated in vitro on solid complex media, the 14 strains of A. carbonarius produced OTA. No other species produced OTA under the same conditions. Among must samples, eight of eleven were found to be contaminated by OTA (concentrations from <10 to 461 ng/L). There is a strong correlation between the presence of ochratoxin-producing strains on grapes and OTA in musts. These findings should be connected with the OTA contamination of human blood in these areas and in France. 相似文献
78.
The near-ubiquity of sexual reproduction in animal species has long been considered a paradox because sexually reproducing individuals transmit only half of their genome to their progeny. Here, we show that the ant Cataglyphis cursor circumvents this cost by using alternative modes of reproduction for the production of reproductive and nonreproductive offspring. New queens are almost exclusively produced by parthenogenesis, whereas workers are produced by normal sexual reproduction. By selectively using sex for somatic growth and parthenogenesis for germline production, C. cursor has taken advantage of the ant caste system to benefit from the advantages of both sexual and asexual reproduction. 相似文献
79.
80.