| 摘要: |
| 海洋盐分主要通过地下水入侵、浪花飞溅、盐雾等方式对滨海植物的根、茎和叶产生影响。采用长势良好2年生夹竹桃（Nerium indicum），分别设置对照0%、0.3%、0.6%、1%、2%、3%多个浓度梯度，开展根系和叶片耐盐实验。盐胁迫处理13周后正常浇水4周。在盐胁迫末期及正常浇水后测定叶片净光合速率（Pn）、蒸腾速率（Tr）、气孔导度（Gs）、水分利用率（WUE）等光合指标；同时测定细胞膜透性、叶片饱和水分亏缺（WSD）等理化指标。结果表明：根系盐胁迫和叶片盐胁迫均会影响夹竹桃植株形态和生长，根系盐胁迫≥1.0%时，夹竹桃植株生长状态向着小于2的趋势发生不可逆下降；叶片盐胁迫≤3.0%时，夹竹桃生长状态普遍大于2。根系盐胁迫极显著降低夹竹桃叶片Pn、Tr和Gs；叶片盐胁迫对夹竹桃植株的Pn和WUE影响极显著，对Tr和Gs无显著影响。夹竹桃Tr与Gs之间极显著相关；高浓度根系盐胁迫下，气孔因素对夹竹桃光合影响较为显著。叶片盐胁迫下，夹竹桃细胞膜透性和WSD变化不显著，高浓度根系盐胁迫下，夹竹桃细胞膜透性和WSD发生不可逆改变；这与生长状态和光合特性的结果可以很好对应，说明膜系统受损反过来影响夹竹桃生长和光合作用。总体上，夹竹桃可耐受3.0%以下的叶片盐胁迫和1.0%以下的根系盐胁迫。将根系和叶片耐盐特性分别研究，可以更好地为夹竹桃在滨海生态和植被修复应用中提供理论指导。 |
| 关键词: 夹竹桃 根系盐胁迫 叶片盐胁迫 光合作用 植物生理 生态修复 |
| DOI：10.20016/j.cnki.hykfygl.20231017.002 |
| 投稿时间：2022-12-05修订日期：2023-07-27 |
| 基金项目:福建省科技计划项目“海堤植被生态化构建技术研究”（2021Y0066）；自然资源部第三海洋研究所基本科研业务费资助项目“典型滨海植物耐盐特性及海岸植被构建适宜性研究”（海三科2020013，海三科2019017）. |
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| Physiological and Photosynthetic Characteristics with Ecological Restoration Application of Nerium indicum Under Salt Stress |
| DING Weilun,CHEN Huiying,TANG Kunxian,SUN Yuanmin,CAI Luchun,MA Yong,ZHANG Fei |
| Third Institute of Oceanography, MNR;Key Laboratory of Marine Ecological Conservation and Restoration, MNR;Fujian Provincial Key Laboratory of Marine Ecological Conservation and Restoration;Third Institute of Oceanography, MNR;Key Laboratory of Marine Ecological Conservation and Restoration, MNR;Observation and Research Station of Island and Coastal Ecosystem in the Western Taiwan Strait, MNR; Fujian Provincial Key Laboratory of Marine Ecological Conservation and Restoration;Third Institute of Oceanography, MNR;Observation and Research Station of Island and Coastal Ecosystem in the Western Taiwan Strait, MNR |
| Abstract: |
| Marine salinity affects mainly the roots, stems and leaves of coastal plants through groundwater intrusion, splashing and salt spray. Two-year-old Nerium indicum L. seedlings with good growth were used to carry out the salt tolerance experiments in their roots and leaves by setting multiple concentration gradients of control 0%, 0.3%, 0.6%, 1.0%, 2.0% and 3.0%. Normal watering for 4 weeks was followed by 13 weeks of salt stress treatment. The net photosynthetic rate (Pn), transpiration rate (Tr), stomatal conductance (Gs) and water use efficiency (WUE) were measured at the end of salt stress and after normal irrigation. At the same time, physical and chemical indices, such as the cell membrane permeability and water saturation deficit (WSD) of leaves, were measured. The results showed that both soil salt stress and foliar salt stress affected the morphology and growth of Nerium indicum. When the soil salt stress was ≥1.0%, the growth status of Nerium indicum decreased irreversibly to less than 2, while under foliar salt stress ≤3.0%, the growth status of Nerium indicum was generally greater than 2. Soil salt stress significantly reduced the Pn, Tr and Gs of Nerium indicum leaves. Foliar salt stress had significant effects on Pn and WUE but no significant effects on Tr and Gs. There was a significant correlation between Tr and Gs; under high-concentration soil salt stress, stomatal factors had a more significant effect on the photosynthesis of Nerium indicum. Under foliar salt stress, the cell membrane permeability and WSD of Nerium indicum did not change significantly. Under high-concentration soil salt stress, the cell membrane permeability and WSD of Nerium indicum changed irreversibly, corresponding well with the results of growth status and photosynthetic responses, indicating that the damage to the membrane system in turn affected the growth and photosynthesis of Nerium indicum. In general, Nerium indicum can tolerate less than 3.0% foliar salt stress and less than 1.0% soil salt stress. Studying the salt tolerance characteristics of roots and leaves can provide theoretical guidance for the application of Nerium indicum in coastal ecology and vegetation restoration. |
| Key words: Nerium indicum, Root-salt stress,Leaf-salt stress,Photosynthesis,Plant physiology,Ecological restoration |
