| 摘要: |
| 为了探究小花老鼠簕（Acanthus ebracteatus）适宜生长的盐度，在温室内采用自动潮汐模拟系统对小花老鼠簕幼苗进行研究。本研究设置8个盐度梯度（0‰、5‰、10‰、15‰、20‰、25‰、30‰、35‰）的胁迫处理，研究盐度胁迫对小花老鼠簕生长指标和生理指标的影响。结果表明，水体盐度为0‰ - 15‰，小花老鼠簕成活率为100%且生长状况良好，生物量、株高增量和基径增量均保持在较高水平；盐度≥20‰小花老鼠簕叶片脱落，出现死亡，且随着盐度的增加，成活率不断下降，盐度30‰和35‰处理一周后小花老鼠簕全部死亡。随着盐度的增加，小花老鼠簕叶片内的过氧化物酶（POD）活性和脯氨酸含量呈上升趋势，且盐度20‰和25‰处理显著高于其他处理（P<0.05）；超氧化物歧化酶（SOD）活性、可溶性糖含量、蛋白含量和丙二醛（MDA）含量先增大后减小，拐点均出现在盐度20‰。叶绿素a、叶绿素b、初始荧光（F0）、最大荧光（Fm）、可变荧光（Fv）和相对电子传递速率（ETR）总体上呈先增后减的趋势；最大光化学效率（Fv/Fm）在各处理组间均无显著差异（P＞0.05）。相关性分析表明，盐度与小花老鼠簕各生长指标均呈显著负相关（P<0.05），盐度的增加对小花老鼠簕的形态指标产生了不同程度的抑制；盐度与小花老鼠簕各生理指标总体上呈显著正相关（P<0.05），酶活性和渗透调节物质对盐度具有较强的响应机制。综合分析表明，小花老鼠簕幼苗可生长于盐度20‰以下，盐度≥20‰对植株生长生理均产生抑制并出现死亡，适宜生长盐度为0‰ - 15‰。 |
| 关键词: 红树植物 小花老鼠簕 盐胁迫 生长指标 生理指标 |
| DOI： |
| 投稿时间：2024-03-04修订日期：2024-04-25 |
| 基金项目:广西科技重点研发计划项目(桂科AB21220020)资助。 |
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| Effect of Salinity on the Growth and Physiology of Endangered Mangrove Plant Acanthus ebracteatus Seedlings |
|
TONG Lihao, GAO Tingwei, LAN Junnan, QUAN Jiahui, ZHONG Yunxu, YAN Bing
|
| (Guangxi Academy of Marine Sciences （Guangxi Mangrove Research Center）) |
| Abstract: |
| In order to explore the salinity suitable for the growth of Acanthus ebracteatus seedlings, an automatic tidal-simulation system was used to study in the greenhouse. In this study, eight salinity gradients (0‰, 5‰, 10‰, 15‰, 20‰, 25‰, 30‰, 35‰) were applied to investigate the effects of salinity stress on growth indexes and physiological indexes of A. ebracteatus. The results showed that the salinity treatment of 0‰ - 15‰ water had a good growth with the survival rate was 100%. The biomass, plant height increment and base diameter increment of A. ebracteatus were all maintained at a high level with the salinity of 0‰ - 15‰. When the salinity was 20‰ and above, the leaves of A. ebracteatus fell off and the plant had died, the survival rate decreased with the increase of salinity. The A. ebracteatus had treated under salt stress with one week, all plant had died with salinity of 30‰ and 35‰. With the increase of salinity, the peroxidase activity and proline content in the leaves of A. ebracteatus showed an increasing trend, and the salinity treatments of 20‰ and 25‰ were significantly higher than those of other treatments (P<0.05). And the Superoxide dismutase activity, soluble sugar content, protein content and malondialdehyde content of A. ebracteatus had increased first and then decreased, and the inflection point appeared at salinity 20‰. Chlorophyll a, chlorophyll b, initial fluorescence, maximum fluorescence, variable fluorescence and relative electron transport rate generally increased first and then decreased. There was no significant difference in maximum photochemical efficiency among all treatment groups (P>0.05). Correlation analysis showed that there was a significant negative correlation between salinity and growth indicators of A. ebracteatus (P<0.05), and the increase of salinity had different degrees of inhibition on the morphological indicators of A. ebracteatus. In general, there was a significant positive correlation between salinity and physiological indicators of A. ebracteatus (P<0.05), and the enzyme activity and osmoregulatory substances have a strong response mechanism to salinity. The comprehensive analysis showed that the A. ebracteatus seedlings can grow in salinity under 20‰, be equal or greater than 20‰ can inhibit its growth, physiology and cause the plant death. The suitable salinity for the growth of A. ebracteatus ranges from 0‰ to 15‰. |
| Key words: mangrove plant Acanthus ebracteatus salt stress growth index physiological index |
