海水胁迫下黄秋葵Na⁺、K⁺含量变化规律研究
Study of the Change Regulation of Na⁺ and K⁺ Contents in Okra under Seawater Stress

黄秋葵(Abelmoschus esculentus L.)为一年生草本植物，具有很高的营养价值。我国有大面积沿海滩涂盐渍化土地，但有关海水胁迫对黄秋葵体内Na⁺和K⁺含量变化规律的研究较少。本研究以耐盐黄秋葵品种无角香蕉和盐敏感品种非洲秋葵为材料，采用50%和100%浓度的海水进行胁迫处理，于第0、4、8、12 d进行取样，分析Na⁺和K⁺含量在黄秋葵体内的变化规律。结果表明，海水胁迫后，黄秋葵体内Na⁺含量和Na⁺/K⁺呈逐渐增加的趋势，K⁺含量呈逐渐下降的趋势。耐盐品种无角香蕉在海水胁迫后，根中积累了较多的Na⁺，而茎和叶中的Na⁺含量则明显低于非洲秋葵；无角香蕉茎和叶中K⁺含量的降低幅度明显小于非洲秋葵；无角香蕉根的Na⁺/K⁺高于非洲秋葵，而茎和叶的Na⁺/K⁺则明显低于非洲秋葵。耐盐品种无角香蕉在受到海水胁迫后根系对Na⁺具有较强的存储功能，叶片则具有较强的Na⁺外排功能；无角香蕉能较好地控制茎和叶中的K⁺含量，并维持其占整株比率的相对稳定。本研究为明确黄秋葵的海水盐胁迫耐受机理以及耐盐黄秋葵新品种选育提供了理论依据。
Okra (Abelmoschus esculentus L.) is an annual herb with high nutritional value. There is a large area of salinized land along the beach in China, but there are few studies on the changes of Na⁺ and K⁺ contents in okra under seawater stress. In this study, 50% and 100% concentrations of seawater were used to treat the salt-tolerant okra cultivar Wujiaoxiangjiao and salt-sensitive cultivar Feizhouqiukui. Samples were taken at 0, 4, 8 and 12 days to analyze the changes of Na⁺ and K⁺ contents in okra. The results showed that after seawater stress, Na⁺ content and Na⁺/K⁺ in okra increased gradually, while K⁺ content decreased gradually. After seawater stress, more Na⁺ was accumulated in the root of salt-tolerant cultivar Wujiaoxiangjiao, while the content of Na⁺ in the stem and leaf was significantly lower than that of Feizhouqiukui. The decrease of K+ content in the stem and leaf of Wujiaoxiangjiao was less than that of Feizhouqiukui. The Na⁺/K⁺ in the root of Wujiaoxiangjiao was higher than that of Feizhouqiukui, while the Na⁺/K⁺ of stem and leaf was lower than that of Feizhouqiukui. After seawater stress, the root of salt-tolerant cultivar Wujiaoxiangjiao has a strong storage function for Na⁺, while the leaf has a strong Na⁺ efflux function. The content of K⁺ in stem and leaf of Wujiaoxiangjiao can be well controlled, and the proportion of K⁺ in the whole plant is relatively stable. This study provides a theoretical basis for understanding the mechanism of salt tolerance of okra and the breeding of new salt-tolerant okra varieties.