【作者】 康孟利；

【导师】 骆耀平；

【作者基本信息】 浙江大学 ， 茶学， 2004， 硕士

【摘要】 本试验以水培和盆栽的浙农117、浙农113和龙井43为材料，对其进行了不同铅浓度的叶面和根部处理，研究了茶树叶片和根系吸收铅之后，铅在茶树体内的累积分布及其在茶园土壤、茶树中的主要存在形态，铅对茶树生育、生理的影响，茶树体内保护酶类活性的变化等，结果表明： 1．铅在茶树体内具有可移动性，叶面吸收的铅可以向地下部转移，根系吸收的铅也可以向地上部运送，并分布于茶树的各个器官中。无论是通过叶面吸收，还是通过根系吸收，铅在茶树体内都表现出相同的累积分布规律：铅被吸收后，在茶树的吸收根和老茎累积量高；地下部的铅含量高于地上部；地下部铅含量依次为，吸收根＞细根＞主根；地上部铅含量的大小依次为，老茎＞嫩叶＞老叶＞嫩茎＞芽。 2．茶树体内铅主要以草酸铅和磷酸氢铅、磷酸铅等难溶于水的磷酸盐的形态存在，其次为果胶酸铅、与蛋白质呈结合态或吸附态的铅，依次为水溶性有机酸铅和磷酸铅、硝酸铅和氯化铅为主的无机物及氨基酸铅。其中，在茶树的根、茎、叶中两种主要形态的铅含量分别为全铅量的97.34％、98.35％和99.65％。根细胞中的铅，主要分布在细胞壁和细胞核中，茎细胞中的主要分布在细胞核中，而叶片细胞中的主要分布在细胞质和细胞壁中。 在未加入铅处理时，铅的存在形态及对应的铅含量大小顺序为硫化物残渣态＞碳酸盐结合态＞吸附态＞有机结合态＞交换态＞水溶性铅，加入外源铅后，变化顺序为硫化物残渣态＞交换态＞碳酸盐结合态＞有机结合态＞吸附态＞水溶性铅，硫化物残渣态和交换态的铅含量相对较高。 3．受铅影响，不同茶树品种生育状态有不同的表现。在试验处理浓度范围内，铅能促进浙农113和龙井43两个品种的生长，具体表现为：新梢生长量增大、百芽重(一芽二叶)和节间长度增加、萌芽期提早。浙农117茶树生长受到抑制，具体表现为：在160mg／kg铅处理浓度下，初期对生长有促进作用，之后作用消失、百芽重(一芽二叶)和节间长度降低、萌芽期推迟。 4．净光合速率测定表明，浙农117在铅的浓度为160mg／kg时，净光合速率已受影响；在试验浓度范围内，铅对浙农113品种的净光合速率影响不大，龙井43品种在160mg／kg浓度条件下对光合作用起到促进作用，430mg／kg铅的处理浓度下对茶树光合作用产生抑制。 三个品种的细胞膜透性变化为，浙农113和龙井43茶树品种细胞膜透性随着错浓度增加有升高现象，但差异未达显著水平;浙农117在铅浓度为16Omg/kg时，细胞膜透性增加不显著，而在4309/kg铅浓度处理下，细胞膜透性发生极显著变化(P<0.01)，细胞膜透性比对照增加了174.57%。 铅处理后茶树体内丙二醛的含量的变化基本与细胞膜透性变化一致，而龙井43茶树品种在两种不同铅处理浓度下，先是显著升高，接着是显著下降。 5.在不同铅浓度的处理下，三个茶树品种体内保护性酶类的活性发生了变化。过氧化物酶活性(POD)增加，浙农117茶树的各处理间的差异达到极显著水平(p<0.01);浙农113茶树的POD活性在铅处理浓度为430mg/kg时，该酶活性显著升高(p<0.05);龙井43的POD活性在160mg/kg铅处理浓度下极显著(p<0.01)升高，430mg/kg铅浓度处理时，POD活性又极显著(p<0.01)下降。 三个茶树品种的超氧歧化酶活性均随着铅浓度的增加而升高，浙农113和龙井43的酶活性在铅处理浓度430mg/kg时，酶活性提高达到极显著水平(p<0.01);浙农117茶树品种的各种铅处理浓度间的超氧歧化酶活性均达到极显著提高(p<0 .01)。 受铅影响，过氧化氢酶活性(CAT)也有升高的表现。三个茶树品种的以T活性在铅处理浓度为160mg/kg下，均显著升高(p<0.05)，当铅处理浓度为43Omg/kg时，浙农117的CAT活性显著下降(p<。.05);浙农1 13和龙井43的CAT活性升高，但均未达到显著水平。 因而，受铅污染的茶园土壤，在之后的一个较长时期内会对茶树生长产生影响。更多还原

【Abstract】 This study examined the characteristics of Pb uptake, accumulation and distribution by tea plant (Camellia sinensis L.) with solution culture and pot experiment. Pb contents were analyzed in samples of absorptive root, radicella root, main root, mature stem, young leaf, mature leaf, young stem and tea shoot were taken from three newly bred varieties, i. e. Zhenongll3 Zhenongll3, and Longjing43, grown in trophic solution and pot trial. After spraying Pb on leaves, adding Pb to the solution and pot soil, a series of physiological index, Pb conformation in vivo, and shoot growth rate, and protective enzyme activities were also investigated. The results showed as follows:1. Pb can be taken up not only by leaves of tea plant and transported to the roots , but also by roots and transported to the upper parts . Pb uptaken can be distributed in all parts of tea plant. The behavior of accumulation and distribution of Pb in tea plant showed similar rules in this two different uptake ways. The concentration of Pb in underground parts was higher than that of aerial parts. The highest concentration was in absorptive roots and mature stems. Pb concentration in underground parts was sequenced as: absorptive roots > radicella roots > main roots. In upper parts, the sequence showed as: mature stems > young leaves > mature leaves > young stems) bud.2. Lead in tea plant is mainly in the form of oxalic acid lead .phosphoric acid hydrogen lead (PbHPO4) and phosphoric acid lead( Pb3(P04 )2) , and some acid hydrogen lead and so on . The contents of main Pb forms in the roots ,stems and leaves are 97. 34% , 98. 35% and 99.65% respectively of the total lead that presents in tea plant . In root, Pb is mainly distributed in cell wall and the cell nucleus . In stem, it is distributed in cell nucleus, and which in cytoplasm and in leaves it is located in cytoplasm and cell wall.In non Pb - treated soil, the sequence of Pb forms in soil is showed as : sulphide united lead >carbonate united lead>adsorbed lead >organic and residual united lead >exchangeable lead > water dissolved lead .After lead is added to soil, the Pb forms are sequenced as : sulphide united lead >exchangeable lead > carbonate united lead > organic and residual united lead >adsorbed lead> water dissolved lead. Sulphide united lead and exchangeable lead contents are higher as compared with other forms.3. The growth of tea plant under the effect of Pb was significantly different among the three varieties. In the concentrations of the experiment, Pb could hasten the growth of Zhenong113 and Longjing43, while the growth of Zhenongll7 was restrained when the concentration was 430rag/kg.4. The net photosynthetic rate also showed different results among the three varieties in the same concentration of Pb (160mg/kg). This Pb concentration restrained the growth of Zhenongll7 greatly and ZhenongllS slightly, while enhanced that of Longjing43. The Pb concentration of 430mg/kg decreased the growth of all the three varieties.The permeability of cell membrane changed after the Pb uptake by tea plant. The permeability of cell membrane in leaves increased lightly with Pb concentration increasing in Zhenongll3 and Longjing43. The permeability increased abruptly in Zhenongll7 when the Pb concentration is 430mg/kg (P < 0.01) and is 174.57% higher than control.The trend of MDA concentration in leaves was similar to the permeability of cell membrane except that in Longjing43.5. The protective enzyme activities in tea plant changed under the Pb treatment. The activity of POD increased in these three varieties .The POD activity in Zhenongll7 increased significantly (p<0. 01) . The POD activity in Zhenongll3 increased significantly (p<0. 05) under the concentration of 430mg/kg . The POD activity in Longjing43 increased significantly (p<0. 01) under the concentration of 160mg/kg , While it dropped significantly (p <0.01) under the concentration of 430mg/kg.In Pb concentration of 430mg/kg , the activities of SOD in ZhenongllS and Longjing43 increased significantly更多还原