Jianyun Ruan

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BACKGROUND AND AIMS Tea (Camellia sinensis) is considered to be acid tolerant and prefers ammonium nutrition, but the interaction between root zone acidity and N form is not properly understood. The present study was performed to characterize their interaction with respect to growth and mineral nutrition. METHODS Tea plants were hydroponically cultured(More)
The levels of extractable aluminum (Al) in soils of tea plantations, Al concentrations in tea leaves and the impact of nitrogen fertilization on these two parameters were investigated. In addition, the properties of soils from tea plantations were compared to those from soils of adjacent non-tea fields to evaluate the effect of land use conversion (from(More)
The concentrations of free amino acids (AA) and polyphenols (PP) are important determinants of green tea quality. Levels of AA and PP are governed interactively by nitrogen (N) supply and carbon (C) status, so the impact of C/N allocation on green tea quality was investigated in saplings cultivated hydroponically with 0.3, 0.75, 1.5 or 4.5 mmol l(-1) N.(More)
Tea plants (Camellia sinensis (L.) O. Kuntze) accumulate high fluoride in the leaves whereas the mechanism on its uptake is poorly understood. The measured F− uptake was compared to calculated uptake from transpiration rates assumuing no discrimination between F− and water to characterize the property of F− absorption by tea plant roots. The F− uptake was(More)
BACKGROUND Free amino acids in young tea shoots are important chemical constituents, remarkably influencing the quality of green teas. Nutrient solution, soil pot and field experiments were conducted to investigate the effect of magnesium nutritional status on accumulation and transport of free amino acids in tea plants (Camellia sinensis (L.) O. Kuntze).(More)
BACKGROUND AND AIMS Tea plants (Camellia sinensis L.) accumulate large amounts of fluoride (F) from soils containing normal F concentrations. The present experiments examined the effects of pH and Ca on F uptake by this accumulating plant species. METHODS The effect of pH was assessed in two experiments, one using uptake solutions with different pHs, and(More)
To investigate the effect of light intensity and temperature on the biosynthesis and accumulation of quality-related metabolites, field grown tea plants were shaded by Black Net and Nano-insulating Film (with additional 2-4°C cooling effect) with un-shaded plants as a control. Young shoots were subjected to UPLC-Q-TOF MS followed by multivariate statistical(More)
The sensory quality of green tea changes greatly within a single spring season, but the mechanism is not clearly elucidated. Young shoots of the early, middle, and late spring season were subjected to metabolite profiling using gas chromatography-time-of-flight mass spectrometry (TOF/MS) and ultraperformance liquid chromatography-quadrupole-TOF/MS.(More)
Metabolomics profiling provides comprehensive picture of the chemical composition in teas therefore may be used to assess tea quality objectively and reliably. In the present experiment, water and methanol extracts of green teas from China were analyzed by ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS)(More)
The effects of litter incorporation and nitrogen application on the properties of rhizosphere and bulk soils of tea plants (Camellia sinensis (L.) O. Kuntze) were examined in a pot experiment. Total of 8 treatments included four levels of tea litter additions at 0, 4.9, 9.8, and 24.5 g kg−1 in combination with two N levels (154.6 mg kg−1 and without). After(More)