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排序方式: 共有1780条查询结果,搜索用时 15 毫秒
131.
Jaciele Beserra de Lira Alberício Pereira de Andrade André Luiz Rodrigues Magalhães Fleming Sena Campos Gherman Garcia Leal de Araújo Diana Signor Deon 《Communications in Soil Science and Plant Analysis》2020,51(5):701-709
ABSTRACTThe objective is to determine the growth, yield and chemical characteristics of pearl millet irrigated with different levels of brackish water and organic matter in two cultivation cycles. The experimental design was randomized blocks in a 4 × 4 factorial arrangement, composed of 4 levels of brackish irrigation (25, 50, 75 and 100% evapotranspiration), 4 levels of organic matter (0, 15, 30 and 45 t ha?1) with 3 repetitions. Along two cultivation cycles, pearl millet crop was analyzed for: plant growth variables, fresh and dry mass production, water-use efficiency, and chemical composition. There was significant interaction between applied water levels and organic matter for lignin in the 2nd cut (P < .05). The number of leaves, number of dead leaves and fresh mass production were influenced by the isolated effect of brackish water levels in cut 1 (P < .05). In turn, fresh mass production, dry mass production, plant height, leaves length, panicle length, fresh mass production, crude protein and ether extract were influenced by the isolated effect of saline water levels in the 2nd cut (P < .05). Growth, biomass production and chemical composition variables in second cut are positively influenced by different brackish irrigation levels under low rainfall conditions. 相似文献
132.
Bicalho B Pereira AS Aquino Neto FR Pinto AC Rezende CM 《Journal of agricultural and food chemistry》2000,48(4):1167-1174
Free and bound volatile components of a Brazilian cashew apple variety (Anacardium occidentale L. var. nanum) were obtained by simultaneous distillation-extraction (SDE) and XAD-2 adsorption. According to gas chromatography-mass spectrometry (GC-MS) analyses and retention indices, 62 free volatile constituents were characterized and quantified. They were esters (40%), terpenes (20%), hydrocarbons (14%), fatty acids (9%), aldehydes (8%), alcohols (3%), lactones (3%), ketones (1%), phenols (1%), and norisoprenoids (1%). The glycosidically bound volatile precursors were analyzed by high-temperature GC-MS, after room temperature silylation. Several conjugated alcohols and cinnamic acids were detected and reported as cashew apple glycosyl constituents for the first time. 相似文献
133.
Pereira AS Norsell M Cardoso JN Aquino Neto FR Ramos MF 《Journal of agricultural and food chemistry》2000,48(11):5226-5230
Methanol extracts of propolis from six different places, five in Rio de Janeiro state and one in S?o Paulo state, both in the Southeast of Brazil, were investigated using high-temperature high-resolution gas chromatography (HT-HRGC) and HT-HRGC-mass spectometry. The main purpose of the study was to establish the applicability of HT-HRGC as an analytical method for systematic studies of polar propolis fractions. Several compounds, including carbohydrates, phenolic acid derivatives, and high molecular weight compounds (e.g., wax esters of long chain fatty alcohols) could be readily characterized in the crude extracts by HT-HRGC-MS. HT-HRGC and HT-HRGC-MS were shown to be quick and informative tools for rapid analysis of crude polar extracts without cleanup. 相似文献
134.
Beatriz Wiebke-Strohm Annette Droste Giancarlo Pasquali Marina Borges Osorio Lauro Bücker-Neto Luciane Maria Pereira Passaglia Marta Bencke Milena Schenkel Homrich Márcia Margis-Pinheiro Maria Helena Bodanese-Zanettini 《Euphytica》2011,177(3):343-354
An Agrobacterium-mediated transformation procedure for soybean [Glycine max L. Merrill] proliferating somatic embryos is here described. The Agrobacterium tumefaciens LBA4404 strain harboring pTOK233, pCAMBIA1390-olp or pH7WG2Dwrky plasmids was used to mediate gene transfer into the plant genome. Prior to Agrobacterium inoculation, proliferative soybean embryogenic clusters were microwounded by DNA-free tungsten particle bombardment. Three
independent transformation experiments were performed. In Experiment I, 26 transgenic plants were obtained from a unique clone
of cv Bragg, while 580 plants were recovered from 105 clones of cv IAS5. In Experiment II, a single hygromycin-resistant clone
of cv BRSMG68 Vencedora was recovered and gave rise to five plants. In Experiment III, 19 plants of cv Bragg and 48 plants
of IAS5 were recovered, representing five and 14 independent transformation events, respectively. PCR and Southern analyses
confirmed the transgenes’ integration into plant genomes. Transgenic plants were fertile. They flowered, set pods and seeds.
Transgene segregation in two T1 progenies fits the Mendelian pattern (3:1 transgenic:non-transgenic plants). This is the first report of transgenic fertile
soybean plants obtained from somatic embryogenic tissues transformed by the system that combines DNA-free particle bombardment
and Agrobacterium. 相似文献
135.
Costa-Mattioli M 《Science (New York, N.Y.)》2008,322(5903):874-875
136.
137.
Sandrelli F Tauber E Pegoraro M Mazzotta G Cisotto P Landskron J Stanewsky R Piccin A Rosato E Zordan M Costa R Kyriacou CP 《Science (New York, N.Y.)》2007,316(5833):1898-1900
Diapause is a protective response to unfavorable environments that results in a suspension of insect development and is most often associated with the onset of winter. The ls-tim mutation in the Drosophila melanogaster clock gene timeless has spread in Europe over the past 10,000 years, possibly because it enhances diapause. We show that the mutant allele attenuates the photosensitivity of the circadian clock and causes decreased dimerization of the mutant TIMELESS protein isoform to CRYPTOCHROME, the circadian photoreceptor. This interaction results in a more stable TIMELESS product. These findings reveal a molecular link between diapause and circadian photoreception. 相似文献
138.
Pereira JR 《Science (New York, N.Y.)》1924,60(1544):102-103
139.
A developmentally regulated neuraminidase activity in Trypanosoma cruzi 总被引:18,自引:0,他引:18
M E Pereira 《Science (New York, N.Y.)》1983,219(4591):1444-1446
The human pathogen Trypanosoma cruzi (Y strain) contains a neuraminidase activity that varies widely in the different developmental stages of the parasite. The specific neuraminidase activity of infective trypomastigotes obtained from tissue culture and from the bloodstream of infected mice is 7 to 15 times higher than that of the acellular culture forms. Amastigotes were devoid of enzyme activity. The enzyme has a pH optimum of 6.0 to 6.5. Live trypanosomes released sialic acid from human erythrocytes and plasma glycoproteins. Several sialyl compounds were hydrolyzed by the parasite, but the best substrate was the protein orosomucoid. Erythrocytes from infected mice with T. cruzi parasitemia were agglutinated by peanut lectin and the hemagglutination titer was correlated with the degree of parasitemia. 相似文献
140.
Marimuthu MP Jolivet S Ravi M Pereira L Davda JN Cromer L Wang L Nogué F Chan SW Siddiqi I Mercier R 《Science (New York, N.Y.)》2011,331(6019):876
Cloning through seeds has potential revolutionary applications in agriculture, because it would allow vigorous hybrids to be propagated indefinitely. However, asexual seed formation or apomixis, avoiding meiosis and fertilization, is not found in the major food crops. To develop de novo synthesis of apomixis, we crossed Arabidopsis MiMe and dyad mutants that produce diploid clonal gametes to a strain whose chromosomes are engineered to be eliminated after fertilization. Up to 34% of the progeny were clones of their parent, demonstrating the conversion of clonal female or male gametes into seeds. We also show that first-generation cloned plants can be cloned again. Clonal reproduction through seeds can therefore be achieved in a sexual plant by manipulating two to four conserved genes. 相似文献