共查询到18条相似文献,搜索用时 203 毫秒
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海平面上升引起潮汐水位降低和淹水时间增加,探明红树林对潮汐淹浸适应的生理生态特性有助于科学保护和修复红树林,而且科学选取红树林营林宜林地也需要了解红树林与潮汐浸淹之间的相互关联。文中从红树林潮汐浸淹的研究方法出发,重点论述水淹胁迫对红树植物形态表征、光合作用、呼吸作用、抗氧化系统、渗透调节物质和化学计量特征的影响,以及潮汐浸淹下红树植物分子生物学机制,以期为揭示红树植物对潮汐浸淹的适应机制以及全球气候变化背景下我国红树林造林实践和宜林地选择提供参考。 相似文献
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对深水裸滩几种红树植物及沼生植物落羽杉的生长适应性研究结果表明:(1)红树植物无瓣海桑与落羽杉的成活率和生长速度较接近,远超过桐花树、秋茄和木榄,证明无瓣海桑和落羽杉对于深水裸滩的生长适应能力较强,具有速生特性;(2)随滩面高度的降低,海水淹浸时间的增加,红树植物和落羽杉的成活率及生长速度有下降的趋势。在滩面高度低于-0.9m时,落羽杉成活和生长极差,各种红树植物则无法成活和生长。落羽杉的耐淹浸能力最强,其次为无瓣海桑,桐花树较差,秋茄和木榄最差;(3)在同一生长地红树植物与落羽杉的生长指标间存在一定的相关性。无瓣海桑与落羽杉之间的生长相关性最为明显,各生长指标间基本上都表现出极显著的相关性,而桐花树、秋茄、木榄与落羽杉的毕长相关性较差。 相似文献
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低磷胁迫条件下,植物将以一系列形态、生理、生化和遗传机制主动适应胁迫环境,包括根系对生长环境中难溶性磷的活化,有效吸收、运转、分配及再利用等.植物通过改变对养分的需求以维持自身代谢和改变根系形态、生理机能来增强自身活化和吸收养分的强度[1].具有较高的磷素吸收能力是植物耐低磷胁迫的基础[2],研究低磷胁迫条件下植物的生理生化特性对揭示耐低磷机理具有重要意义.以往在农作物方面有过一些研究[3~6],但在林木方面研究不多.本试验以不同磷效率的马褂木(Liriodendron chinense (Hemsl.)Sarg.)6个种源为材料,试图研究低磷营养胁迫下马褂木种源在膜脂过氧化、可溶性蛋白含量、叶绿素含量及酸性磷酸酶活性等方面的差异及与磷效率的关系,为优良耐低磷马褂木种源的选育提供理论依据. 相似文献
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代谢组学在植物逆境胁迫研究中的应用 总被引:1,自引:0,他引:1
代谢组学是继基因组学、转录组学、蛋白质组学之后新兴的一门交叉学科, 是系统生物学的一个重要分支, 近年来在研究植物逆境胁迫方面得到了广泛的应用。文中介绍了代谢组学的检测技术、数据处理及分析方法, 概述了其在植物逆境胁迫下的研究概况, 包括温度、盐分、干旱、病原菌和其他逆境, 以及多种逆境综合胁迫等, 展望了代谢组学的发展前景; 利用代谢组学分析植物在逆境条件下代谢物的变化, 推测应答胁迫植物对代谢途径的调整, 可为研究植物耐受性和适应逆境机理提供分析方法。 相似文献
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以1年生澳洲茶树(Melaleuca alternifolia)组培苗为研究对象,采用双套盆法进行盆栽淹水试验,研究淹水胁迫对澳洲茶树生长和生理特性的影响,为其推广种植提供理论依据。结果表明,淹水60 d内叶片不萎蔫,苗木成活率为100%,但苗木生长速度受到一定程度的抑制;过氧化物酶(POD)活性随淹水时间的增加逐渐提高,为淹水胁迫的主要响应酶;超氧化物歧化酶(SOD)活性前10 d波动升高,之后整体呈波动下降的趋势;过氧化氢酶(CAT)活性前16 d较高;硝酸还原酶(NR)活性18~30 d时较高;谷胱甘肽过氧化物酶(GSH-PX)活性呈先升高后下降的趋势,前38 d活性较高;丙二醛(MDA)含量呈连续M型变化后降为胁迫前的水平;脯氨酸含量在16 d时急剧上升;可溶性糖含量呈先增加后降低的趋势。澳洲茶树具有较强的耐涝性,可通过提高保护酶活性和调节代谢逐渐适应淹水环境,但生长速度较慢,为保证其生长速度,在淹水时应及时排水。 相似文献
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Effects of flooding on water transport in mangroves have previously been investigated in a few studies, most of which were conducted on seedlings in controlled settings. In this study, we used heat-dissipation sap probes to determine if sap flow (J(s)) attenuates with radial depth into the xylem of mature trees of three south Florida mangrove species growing in Rookery Bay. This was accomplished by inserting sap probes at multiple depths and monitoring diurnal flow. For most species and diameter size class combinations tested, J(s) decreased dramatically beyond a radial depth of 2 or 4 cm, with little sap flow beyond a depth of 6 cm. Mean J(s) was reduced on average by 20% in Avicennia germinans (L.) Stearn, Laguncularia racemosa (L.) Gaertn. f. and Rhizophora mangle L. trees when soils were flooded. Species differences were highly significant, with L. racemosa having the greatest midday J(s) of about 26 g H(2)O m(-2) s(-1) at a radial depth of 2 cm compared with a mean for the other two species of about 15 g H(2)O m(-2) s(-1). Sap flow at a depth of 2 cm in mangroves was commensurate with rates reported for other forested wetland tree species. We conclude that: (1) early spring flooding of basin mangrove forests causes reductions in sap flow in mature mangrove trees; (2) the sharp attenuations in J(s) along the radial profile have implications for understanding whole-tree water use strategies by mangrove forests; and (3) regardless of flood state, individual mangrove tree water use follows leaf-level mechanisms in being conservative. 相似文献
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Flooding is assumed to cause an energy crisis in plants because-due to a lack of O(2)-mitochondrial respiration is replaced by alcoholic fermentation which yields considerably less energy equivalents. In the present study, the effect of flooding on the carbon metabolism of flooding-tolerant pedunculate oak (Quercus robur L.) and flooding-sensitive European beech (Fagus sylvatica L.) seedlings was characterized. Whereas soluble carbohydrate concentrations dropped in roots of F. sylvatica, they were constant in Q. robur during flooding. At the same time, root alcohol dehydrogenase activities were decreased in beech but not in oak, suggesting substrate limitation of alcoholic fermentation in beech roots. Surprisingly, leaf and phloem sap sugar concentrations increased in both species but to a much higher degree in beech. This finding suggests that the phloem unloading process in flooding-sensitive beech was strongly impaired. It is assumed that root-derived ethanol is transported to the leaves via the transpiration stream. This mechanism is considered an adaptation to flooding because it helps avoid the accumulation of toxic ethanol in the roots and supports the whole plant's carbon metabolism by channelling ethanol into the oxidative metabolism of the leaves. A labelling experiment demonstrated that in the leaves of flooded trees, ethanol metabolism does not differ between flooded beech and oak, indicating that processes in the roots are crucial for the trees' flooding tolerance. 相似文献
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This study investigated the behavior of soluble and particulate manganese, during tidal cycles in a mangrove tidal creek and adjacent mud flats in SE Brazil. We identify the major processes affecting manganese transport to mangroves. The results showed that manganese variability occurs both seasonally, and over the tidal cycle, in response to changing redox potentials. Tidal water flooding mud flats are enriched in manganese, originating from upward migration of reduced species and further adsorption onto suspended particles under oxic conditions. During the tidal cycle, particulate manganese concentrations are higher during flood periods, whilst dissolved concentrations are higher during ebb periods. Although quantitatively different, this pattern occurs both in winter and summer. The dynamics of manganese characterized in this study suggest that this metal may play a significant role as a conveyor of trace metals to mangrove ecosystems, as suggested by earlier studies. 相似文献
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红树林是生长在热带、亚热带海岸潮间带的植物群落,在防浪护堤、净化海水、维护生物多样性等方面发挥着重要作用,是沿海生态系统的重要组成部分。由于历史原因湛江红树林大面积减少,红树林质量明显下降,影响了红树林生态功能的发挥。通过人工造林,能迅速有效恢复红树林资源,提高红树林质量。文章结合湛江地区多年造林实践,对红树林造林技术及相关影响因素作研究分析。 相似文献
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红树植物生长在热带、亚热带海岸滩涂上。健全的红树植物生态系统是人类持续利用红树林的必要条件。如何保护、维持红树林的生态系统及其遗传健全性已成为红树林生态学家最关心的问题。红树植物当前的地理分布格局及形成原因是生态学家和保护生态学家的研究重点。文中介绍了近些年来红树植物亲缘地理学研究概况,包括地理隔离对红树植物分布格局的影响、基因交流受阻隔以及引起红树群体遗传结构变化的原因等内容;阐述了地质历史引起地形地貌变化、地理隔离、繁殖体扩散及生境环境等因子影响红树群体遗传演化的机制;探讨了红树植物亲缘地理学未来研究的重点,以期为红树植物保护和相关研究提供参考。 相似文献
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浅谈文昌市清澜港红树林湿地生态系统存在问题和发展对策 总被引:1,自引:0,他引:1
通过对文昌市清澜港红树林湿地生态系统进行调查,分析清澜港红树林湿地的现状并寻找存在问题,结合生态和红树林湿地可续发展的观点,提出保护和发展清澜红树林湿地生态系统的对策。 相似文献