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Wardatou Boukari Denis Filloux Jean Heinrich Daugrois Emmanuel Fernandez Dimitre Mollov Claudia Kaye Martha Hincapie Alexander Sanchez Jianping Wang Philippe Roumagnac Philippe Rott 《Plant pathology》2020,69(6):1060-1069
Viruses in the genus Mastrevirus (family Geminiviridae), including those infecting sugarcane, have natural geographical ranges almost exclusively restricted to Africa and the Indian Ocean islands off the African coast. Only sugarcane white streak virus (SWSV) in Barbados and sugarcane striate virus (SStrV) in Florida and Guadeloupe are known to infect a few sugarcane varieties in the Western Hemisphere. In this study, PCR assays were developed to detect these two viruses in sugarcane. Five hundred and seventy-one DNA samples from Saccharum species and interspecific hybrids from the Miami World Collection of sugarcane and related grasses were tested for the presence of SStrV and SWSV by PCR. No variety was found infected by SWSV but SStrV was detected in 19 varieties. PCR data were confirmed by sequencing amplified fragments (248 bp). These fragments shared 93%–100% nucleotide identity with SStrV sequences from the GenBank database. SStrV isolates were distributed in six phylogenetic groups, including the four strains of the virus. Most varieties infected by SStrV originated from Asia, thus confirming a previous hypothesis stating that this virus originated from this continent. Absence of SStrV in commercial sugarcane in Florida also suggested that this virus has not been spread in this location, while infected plants have been present for several decades. 相似文献
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Graham Bird Paul A. Brewer Mark G. Macklin Mariyana Nikolova Tsvetan Kotsev Mihail Mollov Catherine Swain 《Water, air, and soil pollution》2010,206(1-4):105-127
Metal dispersal in the Danube and Maritsa drainage basins resulting from metal mining activities in Bulgaria has been assessed through the collection of 611 samples of river water, river channel and floodplain sediment, and mine waste from over 218 sites. Concentrations of Cd, Cu, Pb, and Zn in river water were found to be highest in close proximity to locations of Cu and Pb–Zn mining regions in the Maritsa catchment. Downstream dispersal of solute metals in these catchments, and into the River Danube, was found to be limited by physical dilution and a well-buffered pH environment. Dispersal of contaminant metals in channel and floodplain sediment was found to be extensive. Contamination was particularly severe in the Rivers Timok and Iskar (Danube catchment) and the Topolnitsa, Chepelarska, and Arda Rivers (Maritsa catchment) and creates the potential of transboundary dispersal of contaminant metals. 相似文献
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Ouzounov DG Ahmad FR Müller D Venkataraman N Gallagher MT Thomas MG Silcox J Koch KW Gaeta AL 《Science (New York, N.Y.)》2003,301(5640):1702-1704
The measured dispersion of a low-loss, hollow-core photonic band-gap fiber is anomalous throughout most of the transmission band, and its variation with wavelength is large compared with that of a conventional step-index fiber. For an air-filled fiber, femtosecond self-frequency--shifted fundamental solitons with peak powers greater than 2megawatts can be supported. For Xe-filled fibers, nonfrequency-shifted temporal solitons with peak powers greater than 5.5 megawatts can be generated, representing an increase in the power that can be propagated in an optical fiber of two orders of magnitude. The results demonstrate a unique capability to deliver high-power pulses in a single spatial mode over distances exceeding 200 meters. 相似文献
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Shikov V Kammerer DR Mihalev K Mollov P Carle R 《Journal of agricultural and food chemistry》2008,56(18):8521-8526
Thermal degradation and color changes of purified strawberry anthocyanins in model solutions were studied upon heating at 85 degrees C by HPLC-DAD analyses and CIELCh measurements, respectively. The anthocyanin half-life values increased significantly due to the addition of rose (Rosa damascena Mill.) petal extracts enriched in natural copigments. Correspondingly, the color stability increased as the total color difference values were smaller for anthocyanins upon copigment addition, especially after extended heating. Furthermore, the stabilizing effect of rose petal polyphenols was compared with that of well-known copigments such as isolated kaempferol, quercetin, and sinapic acid. The purified rose petal extract was found to be a most effective anthocyanin-stabilizing agent at a molar pigment/copigment ratio of 1:2. The results obtained demonstrate that the addition of rose petal polyphenols slows the thermal degradation of strawberry anthocyanins, thus resulting in improved color retention without affecting the gustatory quality of the product. 相似文献
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Evidence of potato virus Y asymptomatic clones in diploid and tetraploid potato-breeding populations
Potato virus Y (PVY) is a potyvirus affecting potato productivity by reducing yield and quality. To reduce the amount of PVY in potato production systems, state seed certification agencies have established threshold criteria, which simultaneously increase quality. Research has documented several commercial cultivars lacking symptom expression of PVY despite infection. The presence of PVY asymptomatic clones in production and breeding populations is particularly important because it may provide an inoculum source in breeders’ seed and this reduces the efficiency of selection. The objectives of this research were to determine to what extent PVY asymptomatic clones are present in potato-breeding populations, and if PVY expression is influenced by the environment. After exposure to PVY, genotypes from different 2x and 4x populations were evaluated for the presence of PVY both visually and by ELISA assay. PVY asymptomatic genotypes were identified in both 2x and 4x populations. Chi square indicated dependency between PVY symptom expression and (1) ploidy, (2) genetically distinct 4x germplasm enhancement populations, and (3) expression in a north temperatevs. tropical environment using 4x progeny from five half-sib families. Dependency was not found between two 4x genetically related sub-populations and PVY asymptomatic expression. Analysis of variance (ANOVA) indicated that clones within family, families, location, and the interaction of location by clone were significant sources of variation for PVY symptom expression, ELISA, and visual evaluation. PVY asymptomatic clones were present in both 2x and 4x populations with higher frequencies in a north temperate compared to a tropical environment, suggesting that PVY symptom expression may be influenced by the environment. 相似文献
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Mihalev K Schieber A Mollov P Carle R 《Journal of agricultural and food chemistry》2004,52(24):7306-7310
The effects of enzymatic mash treatments on yield, turbidity, color, and polyphenolic content of cloudy apple juice were studied. Using HPLC-ESI-MS, cryptochlorogenic acid was identified in cv. Brettacher cloudy apple juice for the first time. Commercial pectolytic enzyme preparations with different levels of secondary protease activity were tested under both oxidative and nonoxidative conditions. Without the addition of ascorbic acid, oxidation substantially decreased chlorogenic acid, epicatechin, and procyanidin B2 contents due to enzymatic browning. The content of chlorogenic acid as the major polyphenolic compound was also influenced by the composition of pectolytic enzyme preparations because the presence of secondary protease activity resulted in a rise of chlorogenic acid. The latter effect was probably due to the inhibited protein-polyphenol interactions, which prevented binding of polyphenolic compounds to the matrix, thus increasing their antioxidative potential. The results obtained clearly demonstrate the advantage of the nonoxidative mash maceration for the production of cloud-stable apple juice with a high polyphenolic content, particularly in a premature processing campaign. 相似文献
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