碱性盐胁迫对夏蜡梅生长与离子分布的影响

采用不同浓度的碱性盐(NaHCO₃)溶液对3年生夏蜡梅实生苗进行处理,从形态生长和离子运输途径分析夏蜡梅对碱性盐胁迫的响应机制,为夏蜡梅的合理开发利用提供理论指导。结果表明:夏蜡梅苗高、地径相对生长量、生物量以及根冠比均随着盐碱胁迫的加重而不同程度的减少;随着碱性盐浓度的增加,各器官中 Na⁺含量均高于对照,其排序为:根>叶>茎;低浓度碱性盐胁迫下K⁺含量排序为:茎>根>叶,而高浓度胁迫下K⁺含量排序为:叶>茎>根;Ca²⁺含量排序为:叶>根>茎;夏蜡梅茎、叶中K⁺/Na⁺比值远大于根,叶中Ca²⁺/Na⁺比值远大于茎和根;夏蜡梅K⁺和Ca²⁺根系到茎部的选择运输能力排序:K⁺>Ca²⁺,从茎部到叶片排序为:Ca²⁺>K⁺,而从根系到叶片的选择运输能力基本相同。研究表明,碱性盐胁迫下,夏蜡梅的茎和叶通过吸收K⁺及Ca²⁺以阻止Na⁺的进入,将Na⁺贮存区隔在根系中以减轻盐离子对地上部分的伤害,叶片通过增加对矿质元素的吸收以维持离子平衡。

Effects of alkaline salt stress on growth and ion allocation of Sinocalycanthus chinensis

In this study, the three years old Sinocalycanthus chinensis seedlings were treated with different concentrations of alkaline salts (NaHCO₃) solutions, and the response mechanism of Sinocalycanthus chinensis to alkaline salt stress was analyzed from the morphological growth and ion transport routes, so as to provide theoretical guidance for the rational development and utilization of Sinocalycanthus chinensis. The results showed that the seedling height, relative growth of ground diameter, biomass and root-shoot ratio decreased with the increase of saline-alkali stress. With the increase of saline-alkali concentration, the Na⁺ content in each organ were significantly higher than that in the control group, the sequence was as follows: root>leaf>stem. Under low concentration alkaline salt stress, the K⁺ content sequence was as follows: stem>root>leaf, while under high concentration stress, the K⁺ content sequence was as follows: leaf>stem>root. The Ca²⁺ content sequence was as follows: leaf>root>stem. The K⁺/Na⁺ ratio in the stems and leaves of Sinocalycanthus chinensis was much higher than that in the roots and the Ca²⁺/Na⁺ ratio in the leaves was much higher than that in the stems and roots. The sequence of root-stem selective transport capacity of K⁺ and Ca²⁺: K⁺>Ca²⁺, stem-leaf: Ca²⁺>K⁺, while the root-leaf selective transport capacity was basically the same.In conclusion,under alkaline salt stress, the stems and leaves of Sinocalycanthus chinensis prevented the entry of Na⁺ by absorbing K⁺ and Ca²⁺, separated the Na⁺ storage area in the roots to reduce the damage of salt ions to the aboveground part, and the leaves maintained ion balance by increasing the absorption of mineral elements.