發(fā)布時間：2018-04-01 12:09

  本文選題：鎘　切入點：葉用芥菜　出處：《華中農業(yè)大學》2017年碩士論文

【摘要】：隨著人們生活質量的提高以及對膳食營養(yǎng)的重視,蔬菜每年的消費量也在逐年增加。但是由于近些年來土壤重金屬污染問題的日漸突出,及一些食品安全事件的相繼報道,蔬菜安全生產問題也開始引起人們的高度重視。本研究從生產實踐出發(fā)以篩選低鎘(Cadmium,Cd)積累型葉用芥菜品種為目的,通過研究高、低鎘積累型葉用芥菜品種對鎘的吸收和轉運生理機制,以揭示高、低積累型葉用芥菜品種對鎘吸收和轉運差異機理,從而為確保蔬菜安全生產提供重要的理論依據,為培育低鎘積累型的葉用芥菜品種提供明確的研究方向。研究結果表明,篩選出的高、低鎘積累型葉用芥菜品種地上部鎘積累差異的主要原因來源于其根部對鎘的吸收和積累差異,具體研究結果如下:1、不同鎘積累型葉用芥菜品種的篩選通過統計分析并結合生產實踐的要求篩選出了高、低鎘積累型的葉用芥菜品種:低鎘積累型品種2(扁哈大肉芥菜)和高鎘積累型品種4(水東燈籠甜脆芥菜)。2、不同鎘積累型葉用芥菜品種對鎘的轉運特征相關性分析發(fā)現這兩種鎘積累型葉用芥菜品種木質部鎘積累速率與培養(yǎng)介質中鎘濃度有顯著相關性(p0.05),但地上部鎘積累量與木質部鎘積累速率并不成線性關系,這表明了鎘從根部向地上部運輸及裝載時會遇到一定的阻控作用。方差分析發(fā)現這兩種鎘積累型葉用芥菜品種木質部鎘積累速率存在顯著差異(p0.05),但是對鎘的轉運系數并無顯著差異(p0.05),這很可能是由于二者地上部分對鎘的裝載速率差異彌補了木質部鎘積累速率的差異從而造成了整個鎘脅迫時間段內二者對鎘的轉運系數無顯著差異,這也從側面反映了鎘從地下部向地上部轉運的這個過程并不是造成這兩種鎘積累型葉用芥菜品種地上部鎘積累差異的主要決定因素。3、不同鎘積累型葉用芥菜品種根部鎘的亞細胞積累特征通過研究鎘在根部的亞細胞積累規(guī)律發(fā)現,在鎘脅迫情況下低鎘積累型葉用芥菜品種鎘在根部亞細胞組分中的分配情況與高鎘積累型葉用芥菜品種相比具有顯著差異(p0.05),且低鎘積累型葉用芥菜品種在鎘脅迫下,鎘在其根部細胞壁組分的百分含量有所增加,鎘在其根部可溶性組分的百分含量有所減少,推測低鎘積累型葉用芥菜品種有可能通過根部細胞壁對鎘的固定作用來減少鎘向地上部的轉運;通過比較低鎘積累型葉用芥菜品種與高鎘積累型葉用芥菜品種根部鎘的各化學形態(tài)百分含量發(fā)現,低鎘積累型葉用芥菜品種根部乙醇提取態(tài)、氯化鈉提取態(tài)、醋酸提取態(tài)、鹽酸提取態(tài)鎘含量與高鎘積累型葉用芥菜品種相比存在顯著差異(p0.05)。且在鎘脅迫情況下低鎘積累型葉用芥菜品種醋酸提取態(tài)、鹽酸提取態(tài)鎘的百分含量有所增加,推測低鎘積累型葉用芥菜品種有可能通過在根部把鎘轉化成移動活性比較低的化學形態(tài)來減少鎘向地上部的轉運。4、鎘脅迫下不同鎘積累型葉用芥菜品種根系分泌物分泌特性通過研究不同鎘積累型葉用芥菜品種根部對鎘的富集情況及根系分泌物分泌特性發(fā)現,高鎘積累型葉用芥菜品種根部對鎘的富集能力要顯著高于低鎘積累型葉用芥菜品種(p0.05),高鎘積累型葉用芥菜品種根系分泌物中3-甲基-2-氧丁酸的百分含量要明顯高于其它被檢出的根系分泌物百分含量,而低鎘積累型葉用芥菜品種只有在高濃度鎘處理情況下才檢測出3-甲基-2-氧丁酸,推測3-甲基-2-氧丁酸可能會對高積累型葉用芥菜從介質中吸收鎘具有很大的促進作用。
[Abstract]:With the improvement of people's living quality and nutritional value, consumption of vegetables each year is increasing year by year. But due to the heavy metal pollution problems have become increasingly prominent, and some have reported incidents of food safety, safety vegetable production also began to attract people's attention. This study from the production practice to screening of low cadmium (Cadmium, Cd) accumulation in leaf mustard varieties for the purpose, through the research of high, low Cd accumulation in leaf uptake and translocation of cadmium and physiological mechanism of mustard varieties, in order to reveal the high and low accumulation of leaf mustard varieties on cadmium absorption and transport mechanism of different, so as to provide an important theoretical basis the safe production of vegetables, for the cultivation of low cadmium accumulation in the leaf mustard varieties provide clear direction. The results show that the selected high and low Cd accumulation in leaf mustard varieties shoot CD The main reason of the difference of accumulation from the roots and accumulation of Cd uptake, the results are as follows: 1. Different Cd accumulation type leaf mustard cultivars screened by statistical analysis and combining with production practice, the requirements of selected high and low cadmium accumulation in the leaf mustard dishes: low Cd accumulation type 2 (Kazakhstan flat meat mustard) and high cadmium accumulation of 4 varieties (East.2, lantern sweet mustard) with different Cd accumulation in leaf mustard varieties on cadmium transport characteristics correlation analysis found that the two types of Cd accumulation in leaf mustard varieties xylem cadmium accumulation rate and there was a significant correlation between Cd concentration in the culture medium (P0.05), but the cadmium accumulation and xylem Cd accumulation rate is not a linear relationship, suggesting that cadmium from root to shoot transport and loading will have certain control effect. Variance analysis showed that the two type of Cd accumulation in leaf mustard Varieties of xylem cadmium accumulation rate had significant difference (P0.05), but there is no transfer coefficient of CD was significant difference (P0.05), which is likely due to the differences in two on the part of the CD loading rate difference for xylem cadmium accumulation rate and caused no significant difference in the time of cadmium stress transfer coefficient in two on the CD, which is also reflected from the side of cadmium from root to shoot transport of this process is mainly caused by the two kinds of decision Cd accumulation type leaf mustard varieties shoot Cd accumulation factor of.3, different Cd accumulation type leaf mustard varieties root subcellular Cd accumulation characteristics through the research the root of the accumulation of cadmium in subcellular found that compared with mustard varieties in the distribution of cadmium stress under the condition of low Cd accumulation in leaf mustard varieties of Cd in roots in subcellular fractions with high Cd accumulation in leaf has Significant differences (P0.05), and low cadmium accumulation in leaf mustard varieties under cadmium stress, content of cadmium in the root cell wall components increased, content of cadmium in the root soluble fractions decreased, presumably low cadmium accumulation in leaf mustard varieties may be reduced to CD the transport through the root cell wall immobilization of cadmium; by relatively low Cd accumulation in leaf mustard varieties and found high Cd accumulation type leaf with the chemical speciation content of root mustard varieties of cadmium, cadmium accumulation type low extractable leaf mustard varieties root ethanol, sodium chloride extractable, acetic acid extraction state, HCl extractable cadmium content and high Cd accumulation in leaf mustard varieties showed a significant difference (P0.05). And in the case of low cadmium cadmium accumulation in leaf mustard varieties of acetic acid extraction, the extraction percentage of cadmium increased hydrochloric acid, that is low Cadmium accumulation in leaf mustard varieties may put into chemical forms of cadmium through mobile activity is relatively low to reduce CD translocation of.4 in roots under Cadmium Stress of different cadmium accumulation type leaf secretion characteristics of mustard varieties root exudates by different Cd accumulation type leaf mustard varieties root accumulation and root exudates the cadmium secretion characteristics found that high cadmium accumulation in leaf mustard varieties root accumulation capacity of CD was significantly higher than low Cd accumulation in leaf mustard varieties (P0.05), high cadmium accumulation in leaf with percent of mustard varieties in root exudates of 3- methyl -2- butyric acid was higher than that of other oxygen was detected in root secretions content percent and low Cd accumulation type leaf mustard varieties only in high concentrations of cadmium treatment conditions to detect 3- -2- oxygen methyl butyric acid, 3- methyl butyric acid -2- that might be of high oxygen accumulation in leaves The use of mustard to absorb cadmium from medium has a great effect.

【學位授予單位】：華中農業(yè)大學
【學位級別】：碩士
【學位授予年份】：2017
【分類號】：X503.231;S637

【參考文獻】

相關期刊論文 前10條

1 鄒圓;王曉龍;陳瑤瑤;陳學隨;徐R，

本文編號：1695499