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Research for Fluoride Uptake Kinetics Characteristic of Tea Plant

Author: ZhangLei
Tutor: RuanJianYun
School: Chinese Academy of Agricultural Sciences
Course: Tea Science
Keywords: tea plants fluorine absorption dynamics characteristic
CLC: S571.1
Type: Master's thesis
Year: 2008
Downloads: 128
Quote: 1
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Abstract

There are some amounts of fluorine in tea, and peoples could absorb some amounts of fluorine by drinking tea. In this paper, the fluorine absorption characteristics in tea plants were studied. The main studied contents contained the fluorine absorption compared experiments between the tea seedling plants and tomato seedling plants, the influence factors to the absorption of fluorine in tea plants and the absorption dynamics of fluorine in tea plants.1. At the same experiment condition, the differents of fluorine absorption between tea plants and the tomato plants were compared. The fluorine concentration grads from the low level to high level in the absorbed solution were designed as 0.4mg/L(low), 1mg/L(medium), 3.5mg/L(high) each other. The total absorbing time was 24h, and the results showed that the fluorine concentration in the absorbed solution which was absorbed by the tea plants was decreased significant, but the fluorine concentration in the absorbed solution which was absorbed by the tomato plants was not decreased significant. This results illustrated that the two varieties plants has different absorption character to the fluorine, the tea plants has the high absorbing ability to the fluorine but the tomato plants almost rejected to absorb the fluorine.2. The influence on the fluorine absorption in tea plants of temperature, relatively humidity and the pH value of absorbed solution1) The external temperature has great influence on the fluorine absorption. This experiment has compared the fluorine absorption rate in tea plants under 5℃、15℃、25℃、35℃four temperature conditions separately. The results showed that the fluorine absorption rate increased significantly followed the temperature’s going up. When the temperature was lower than 5℃, the fluorine absorption rate in tea plants was very weak, and when the temperature went up to 15℃, the fluorine absorption rate in tea plants was doubled, when the temperature went up to 35℃, the fluorine absorption rate in tea plants was triple of the absorbing rate of 5℃.2) The influence on the fluorine absorption in tea plants with low, medium and high concentration fluorine solutions under two different relatively humidity levels conditions (20% and 90%) has been compared. When the fluorine concentration was not higher than the medium level, changing the relatively atmosphere humidity moisture level condition has no significantly influence on the fluorine absorption in tea plants. But when the fluorine concentration was in the high level, the fluorine absorbing amount followed by the transpiration which was under the lower relatively atmosphere humidity moisture level condition (20%) would significantly higher than that under the higher relatively atmosphere humidity moisture level condition (90%).3) The pH value of absorbed solution would have strong influence on the fluorine absorption. When the pH value of absorbed solution was 6, the fluorine absorption rate in tea plants was very weak, and when the pH value was 4 or 5, the fluorine absorption rate in tea plants was higher. When the tea seedling plants were transferred from the weak acid surrounding into the strong acid surrounding, the fluorine absorption would be increased quickly in a very short time, but this quickly absorbing state would disappear with the time’s going.4) The influence of inhibitors on the fluorine absorption. Such as the CCCP、NFA、A-9-C and so on , all of them could strong restrain the tea plants to absorb the fluorine. And the NFA has the strongest restraining effect in those inhibitors, the average absorbing rate after used the NFA was only the one seventh compare the control. But the inhibitors had no influence on the fluorine absorbing rate drived by the transpiration.3. In this paper, the general exhaustion method and the improved exhaustion method were adopted to study the absorption dynamics parameter of fluorine in tea plants, and the determination method and the datum process method were researched. Results showed that the improved exhaustion method was a better one. when the fluorine concentration was lower in the tea plants root system , the fluorine absorption dynamics curve answered for the model of Michalis- Menten. The Vmax value gained from construction method and Sigma Plot analysis software was 2.605(μg/g·h DW)、3.419(μg/g·h DW) respectively. The Km values was 0.385 mg/L、0.541 mg/L respectively.The results showed that the absorbed fluorine drived by the transpiration couldn’t illustrate the total fluorine in the tea plants, when the fluorine concentration was lower in the tea plants root system , the fluorine absorption dynamics curve answered for the model of Michalis- Menten. It showed that the absorption of fluorine in tea plants maybe exist a proactive process. But when the root system of tea plant were set into a higher fluorine absorbed solution, the absorbing amount of fluorine of tea plant was increased linearity followed the fluorine concentration’s raised. It showed that the absorption of fluorine in tea plants maybe exist a passive process. The proactive process of the absorption of fluorine in tea plants maybe relate to the energy metabolism, the anion passage of S-model and the anion passage secreted by organic acid.

Research for Fluoride Uptake Kinetics Characteristic of Tea Plant

Abstract

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