土壤施硒对茶树叶片硒及矿质元素含量的影响

Effects of Selenium Application on the Concentrations of Selenium and Mineral Elements in the Leaves of Tea Plant

以茶树为试材,亚硒酸钠和硒酸钠为硒源,采用土壤沟施的方式,进行田间试验,研究茶树叶片总硒、有机硒及K、Ca、Mg、Zn、Fe含量变化规律。结果表明,土壤施硒可显著提高叶片总硒和有机硒含量,叶片总硒含量随着施肥浓度增加显著升高,随着采样时间延长,先升高后降低,在施肥后5个月达到最大值。茶树对Se(VI)的吸收和转运能力远高于Se(IV),硒酸钠处理叶片总硒含量是亚硒酸钠处理的10.4~25.3倍。茶树吸收无机硒后大部分都转化为较为安全的有机硒,有机硒占总硒比例为91.6%~96.2%。土施不同浓度硒肥,叶片K、Ca、Mg、Zn、Fe含量呈现出波动式升降变化的特点,施硒显著提高嫩叶Zn含量,并显著降低老叶Ca、Fe含量,对叶片K、Mg含量无显著影响。

A field experiment was conducted to analyze the changes in the contents of total Se, organic Se, K, Ca, Mg,Zn, and Fe in leaves of tea plant by using sodium selenite and sodium selenate as the exogenous Se sources. Results showed that the contents of total Se and organic Se in leaves were increased significantly with the Se application. The total Se content in leaves was significantly increased with the concentrations of Se application. The Se content in leaves was increased first and reached the maximum value at the fifth month after fertilization, and then decreased. The absorption and transport capacity of selenate was far more than that of selenite by tea plant. The Se content in leaves in the selenate treatment was 10.4 to 25.3 times higher than that in the selenite treatment. Most of the inorganic Se was converted to the safe organic Se in leaves. The proportion of organic Se in total Se ranged from 91.6% to 96.2%.The changes in the contents of K, Ca, Mg, Zn, and Fe in leaves were fluctuated in different Se treatments. Exogenous Se significantly increased the content of Zn in young leaves, and significantly decreased the contents of Fe and Ca in old leaves under a certain Se concentration, but had no significant effect on K and Mg contents in leaves.