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Summary S1 to S5 inbred lines, derived from a maize population bred for its overall resistance to three tropical viruses, were screened for resistance to maize streak virus (MSV) by artificial plant infection using viruliferous leafhoppers. Symptoms were rated and intra-line frequency distributions studied for all pedigree inbred lines. Mortality due to MSV was very low among these inbreds. Symptoms appeared later, developed slower and were less severe than in the susceptible control hybrid. Results of a study of 500 S1 and 93 S2 lines suggested that resistance is under genetic control via a system involving loci with major genes (with dominance for resistance) controlling high to complete resistance, associated with a genetic system involving loci with minor genes controlling partial resistance. Lines expressing complete resistance to MSV were developed from 5 cycles of inbreeding and selection. The relevance of such complete and partial resistance is discussed.Abbreviations MRPS
Mean Rating for Plants exhibiting Symptoms 相似文献
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Keim H de Revel G Marchand S Bertrand A 《Journal of agricultural and food chemistry》2002,50(21):5803-5807
Qualitative and quantitative analyses of N-heterocycle compounds were conducted by using a liquid-liquid extraction followed by additional chemical silica gel purification and injection into a gas chromatographic (GC) column coupled to a nitrogen-phosphorus detector (NPD). The purified extract fraction was investigated by GC-NPD and by GC-mass spectrometry. The compounds identified and quantified in wines were 2,4,5-trimethyloxazole, 2,4-dimethylthiazole, and 4-methylthiazole by GC-NPD and both 2-acetylthiazole and 2-acetyl-2-thiazoline by GC-MS. The procedure was used to analyze different wines and gave reliable and reproducible results. 相似文献
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Marchand S de Revel G Vercauteren J Bertrand A 《Journal of agricultural and food chemistry》2002,50(21):6160-6164
Under conditions close to those of wine, that is, low pH, aqueous medium, and low temperatures, this work describes N-(2-sulfanylethyl)-2-oxopropanamide (1), a new intermediate in the formation of 2-acetylthiazole from methylglyoxal and cysteine. 1 was characterized by MS, derivatization MS, and (1)H and (13)C NMR and was synthesized from 2-sulfanylethanamine and ethyl pyruvate. A formation pathway for 2-acetylthiazole from methylglyoxal and cysteine is proposed, in which 1 is a new intermediate in Maillard-type reactions in systems under mild conditions. 相似文献
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An inherited functional circadian clock in zebrafish embryos 总被引：1，自引：0，他引：1
Circadian clocks are time-keeping systems found in most organisms. In zebrafish, expression of the clock gene Period3 (Per3) oscillates throughout embryogenesis in the central nervous system and the retina. Per3 rhythmic expression was free-running and was reset by light but not by the developmental delays caused by low temperature. The time of fertilization had no effect on Per3 expression. Per3 messenger RNA accumulates rhythmically in oocytes and persists in embryos. Our results establish that the circadian clock functions during early embryogenesis in zebrafish. Inheritance of maternal clock gene products suggests a mechanism of phase inheritance through ovogenesis. 相似文献
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Gundlach ER Boehm PD Marchand M Atlas RM Ward DM Wolfe DA 《Science (New York, N.Y.)》1983,221(4606):122-129
The Amoco Cadiz oil spill (223,000 metric tons) of March 1978 is the largest and best studied tanker spill in history. Of the total oil lost, 30,000 tons (13.5 percent) rapidly became incorporated into the water column, 18,000 tons (8 percent) were deposited in subtidal sediments, 62,000 tons (28 percent) washed into the intertidal zone, and 67,000 tons (30 percent) evaporated. While still at sea, approximately 10,000 tons of oil were degraded microbiologically. After 3 years, the most obvious effects of the spill have passed, although hydrocarbon concentrations remain elevated in those estuaries and marshes that were initially most heavily oiled. 相似文献
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Approaches to wine aroma: release of aroma compounds from reactions between cysteine and carbonyl compounds in wine 总被引：1，自引：0，他引：1
Under conditions close to those of wine, that is, low pH, aqueous medium, and low temperatures, this work examines the role of carbonyl (acetoin and acetol) and dicarbonyl (glyoxal, methylglyoxal, diacetyl, and pentane-2,3-dione) compounds associated with cysteine in the formation of odorous products. In particular, thiazole, 4-methylthiazole, 2-acetylthiazole, and trimethyloxazole and two sulfur and oxygenated heterocyclic compounds, 2-furanmethanethiol and thiophene-2-thiol, are examined. For thiophene-2-thiol, the reactional mechanism is proposed. Attempts were made to detect these compounds in wines from various origins. Certain molecules were identified for the first time in wine. 相似文献
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Boucher Dominique Gauthier Sylvie Thiffault Nelson Marchand William Girardin Martin Urli Morgane 《New Forests》2020,51(4):543-571
New Forests - Climate change is projected to increase fire severity and frequency in the boreal forest, but it could also directly affect post-fire recruitment processes by impacting seed... 相似文献
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Pierre-André Marchand David L. Straus Andreas Wienke Lars-Flemming Pedersen Thomas Meinelt 《Aquaculture International》2013,21(3):679-686
The use of peracetic acid (PAA) in aquaculture has been suggested as an alternative therapeutic agent. Few data are available concerning fish toxicity by PAA or factors that modify this toxicity. The aim of this study was to investigate the influence of water hardness on the acute toxicity of PAA products to embryos of zebrafish (Danio rerio). Embryos were exposed to PAA ranging from 0 to 9 mg/L in low-hardness (1.4 °dH or 25 mg/L hardness as CaCO3), medium-hardness (14 °dH or 250 mg/L hardness as CaCO3) and high-hardness (140 °dH or 2,500 mg/L hardness as CaCO3) waters. The lowest LC50 value was 2.24 mg/L PAA in the low-hardness water, and the highest LC50 value was 7.14 mg/L PAA in the high-hardness water. Toxicity of PAA to embryos was found to be negatively correlated with water hardness. The pH decreased with increasing concentrations of PAA, and the test waters were observed to become more acidic in low hardness. In conclusion, aquaculturists using PAA should pay attention to water hardness to avoid acidosis. 相似文献