Adaptation of rhizome connections in drylands: increasing tolerance of clones to wind erosion.
Adaptation of rhizome connections in drylands: increasing tolerance of clones to wind erosion.
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DOI：
10.1093/aob/mcn119
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发表时间：
2008-10
期刊：
影响因子：
4.2
通讯作者：
F. Yu;Ning Wang;Weiming He;Y. Chu;Ming Dong-
中科院分区：
文献类型：
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作者：
F. Yu;Ning Wang;Weiming He;Y. Chu;Ming Dong-
背景和目的风蚀对于旱地植物来说是一种严重的胁迫，但植物抵御侵蚀的机制仍然很大程度上未知。在这里，我们验证了维持根茎连接有助于植物耐受侵蚀的假设。方法在内蒙古某内陆沙丘上设置5条样线，对45块沙沙的叶数、分株生物量和根茎深度进行测量。在另一个沙丘上的 40 x 40 厘米 P. villosa 地块中，顶部 15 或 30 厘米的沙子被去除 1.5 或 3 个月，以分别模拟短期和长期的中度和重度侵蚀，以未经处理的地块作为对照，并切断一半地块边缘的根茎，以模拟根茎连接的丧失。主要结果 每个分株的叶数和生物量与根茎深度呈二次关系；当根茎暴露在空气中时，相关的分株要么死亡，要么变得非常脆弱。每块地的分株数、叶片数和生物量随着侵蚀严重程度的增加而减少。根茎连接在控制或短期侵蚀下不会影响这些性状，但在长期侵蚀下会增加它们。结论 根茎连接减轻了侵蚀对长毛 P. villosa 的负面影响，很可能是因为遭受侵蚀的分株接收了从未受到侵蚀的连接分株转移来的水和/或光合产物。这项研究提供了第一个证据，表明维持根茎连接有助于植物耐受旱地的侵蚀。
BACKGROUND AND AIMS Wind erosion is a severe stress for plants in drylands, but the mechanisms by which plants withstand erosion remain largely unknown. Here, the hypothesis is tested that maintaining rhizome connections helps plants to tolerate erosion. METHODS Five transects were established across an inland dune in Inner Mongolia, China, and measurements were made of leaf number, biomass per ramet and rhizome depth of Psammochloa villosa in 45 plots. In 40 x 40 cm plots of P. villosa on another dune, the top 15 or 30 cm of sand was removed for 1.5 or 3 months to simulate short- and long-term moderate and severe erosion, respectively, with untreated plots as controls, and the rhizomes at the edges of half of the plots were severed to mimic loss of rhizome connections. KEY RESULTS Leaf number and biomass per ramet showed quadric relationships with rhizome depth; when rhizomes were exposed to the air, the associated ramets either died or became very weak. Ramet number, leaf number and biomass per plot decreased with increasing erosion severity. Rhizome connections did not affect these traits under control or short-term erosion, but increased them under long-term erosion. CONCLUSIONS Rhizome connections alleviated the negative effects of erosion on P. villosa, very likely because the erosion-stressed ramets received water and/or photosynthates translocated from those connected ramets that were not subject to erosion. This study provides the first evidence that maintaining rhizome connections helps plants to tolerate erosion in drylands.