Growth and physiological responses of neotropical mangrove seedlings to root zone hypoxia.
Growth and physiological responses of neotropical mangrove seedlings to root zone hypoxia.
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DOI：
10.1093/treephys/16.11-12.883
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发表时间：
1996-11
期刊：
影响因子：
4
通讯作者：
K. McKee
中科院分区：
文献类型：
--
作者：
K. McKee
根霉实生苗、白骨壤幼苗Stearn.和总花环菌(Laguncularia racemosa(L.)加尔特恩。在充气或氮气吹扫的溶液中培养12周，以评估它们对低氧压的相对反应。三个树种对低氧处理的响应都是通过改变生理和形态模式来减少根呼吸的碳损失。然而，低氧处理对幼苗生理和形态的影响程度因种而异。红曲霉维持根氧浓度、根呼吸速率和根伸长速率的能力表明，在对根系形态和生理影响最小的情况下，能够避免低氧胁迫。相反，在处理后的6h内，发芽乳杆菌和总状花序根部的氧气浓度从16%下降到5%或更低。根低氧显著降低了根的呼吸速率(比对照低31%和53%)和根伸长速率(比对照低38%和76%)，这表明这两个物种对根区低氧胁迫的脆弱性比马尾松大。研究结果表明，在厌氧土壤中生长的红树幼苗的相对表现受树种间根系通气性差异及其对根系形态和生理影响的影响。
Seedlings of Rhizophora mangle L., Avicennia germinans (L.) Stearn., and Laguncularia racemosa (L.) Gaertn. f. were cultured in aerated or N(2)-purged solution for 12 weeks to assess their relative responses to low oxygen tensions. All three species responded to low oxygen treatment by modifying physiological and morphological patterns to decrease carbon loss by root respiration. However, the extent to which seedling physiology and morphology were altered by low oxygen treatment differed among species. Maintenance of root oxygen concentrations, root respiration rates and root extension rates by R. mangle demonstrated an ability to avoid low oxygen stress with minimal changes in root morphology and physiology. In contrast, oxygen concentrations in A. germinans and L. racemosa roots declined from 16 to 5% or lower within 6 h of treatment. Root hypoxia led to significant decreases in respiration rates of intact root systems (31 and 53% below controls) and root extension rates (38 and 76% below controls) by A. germinans and L. racemosa, respectively, indicating a greater vulnerability of these species to low oxygen tensions in the root zone compared with R. mangle. I conclude that the relative performance of mangrove seedlings growing in anaerobic soils is influenced by interspecific differences in root aeration and concomitant effects on root morphology and physiology.