| 摘要: |
| 为了探究盐胁迫下外源钙对木麻黄 Casuarina equisetifolia 幼苗生长生理方面的影响，揭示外源钙对木麻黄幼苗盐害的缓解作用，以木麻黄幼苗为试验材料，采用水培方法分析了 0~160 mmol · L-1 NaCl + 0~30 mmol · L-1 CaCl2 处理下幼苗存活率、盐害率、离子含量及质膜透性的变化。结果表明：木麻黄幼苗盐敏感性较强，在 120 mmol · L-1 NaCl（S3C0）处理下，幼苗存活率为 48.6%、盐害率 51.4%，而在该盐浓度附加 15 mmol · L-1 CaCl2（S3C1）处理下，幼苗存活率提升至 92.8%、盐害率降为 6.7%。X- 射线根系微区离子含量分析发现，相较 S3C0 处理，S3C1 处理下 Na+、Cl-相对含量下降，K+、Ca2+、Mg2+ 含量上升，但 Cl-降幅明显低于 Na+，且中柱 Cl-含量偏高，Cl-区室化差。整体上看，S3C1 处理下 K+/Na+、Ca2+/Na+ 大于 Mg2+/Na+，膜系统 Ca2+ 亚细胞化学定位增强，质膜透性减小。说明外源钙能有效增强膜系统稳定性，增加植株对 K+、Ca2+ 吸收利用，盐害程度减弱，木麻黄幼苗耐盐性显著提高。 |
| 关键词: 盐胁迫 外源钙 木麻黄 离子吸收 膜损伤 |
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| Responses of Growth and Physiology to Exogenous Calcium in Casuarina equisetifolia Seedlings under Salt Stress |
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CHEN Liquan, HUANG Canxiong, SU Yiqiang
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Huilai Ecological Forest Management Center
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| Abstract: |
| The effects of exogenous calcium on the growth physiological indexes of Casuarina equisetifolia seedlings under salt stress were investigated by hydroponics, so as to reveal the alleviating effect of exogenous calcium on the salt injury of C. equisetifolia seedlings and provide scientific reference for efficient cultivation of C. equisetifolia seedlings in coastal areas. The results show that C. equisetifolia seedlings were highly sensitive to salt. Under 120 mmol · L-1 NaCl (S3C0) treatment, seedling survival rate was 48.6% and salt injury rate was 51.4%, while under the NaCl concentration plus 15 mmol · L-1 CaCl2 (S3C1) treatment, seedling survival rate increased to 92.8% and salt injury rate decreased to 6.7%. Compared with S3C0 treatment, the relative contents of Na+ and Cl- decreased under S3C1 treatment, while the contents of K+, Ca2+ and Mg2+ increased, but the decrease of Cl- was significantly lower than that of Na+. Moreover, the content of Cl- in the middle column was higher, and the Cl- partitioning was poor. On the whole, K+/Na+ and Ca2+/Na+ were greater than Mg2+/Na+ under S3C1 treatment, Ca2+ cytochemical localization of membrane system was enhanced, and plasma membrane permeability was decreased. These results indicated that exogenous calcium could effectively enhance the stability of
membrane system, increase K+ and Ca2+ absorption and utilization, reduce the salt injury degree, and significantly improve the salt tolerance of C. equisetifolia seedlings. |
| Key words: salt stress exogenous calcium Casuarina equisetifolia ion absorption membrane damage |
