托鲁斯-马戈坑有助于针叶树与血管精子植物竞争
Jarmila Pittermann1, John S Sperry, Uwe G Hacke
1Department of Biology, University of Utah, 257S 1400E, Salt Lake City, UT 84112, USA.
Science (New York, N.Y.)
|December 24, 2005
概括
针状树木的气管,与血管精子的血管不同,具有独特的体-马尔戈坑,可以显著降低水流阻力. 这种适应对于针叶树在各种生态系统中的生存至关重要.
科学领域:
- 植物解剖学 植物解剖学
- 克西勒姆液压系统是什么
- 进化生物学是进化的生物学.
背景情况:
- 针状树木的气管是单细胞的,而血管精子的血管是多细胞的.
- 人们预计,由于长度较短和端壁较靠近,气管体具有较高的流动阻力.
- 人们认为胞体容器在液压上优越.
研究的目的:
- 为了比较针叶树的水力电阻力和胞体的血管.
- 为了研究坑洞结构在体水运输中的作用.
- 为了理解针叶树坑膜的进化意义.
主要方法:
- 对轨迹和容器电阻的比较分析.
- 测量坑膜阻力的液压测量.
- 模拟针叶植物和苗植物的水流阻力.
主要成果:
- 气管和血管表现出类似直径的可比电阻.
- 针叶树末壁坑显示,每面积的流动阻力比船舶坑低59倍.
- 针叶树坑膜的体-体结构显著降低了液压阻力.
结论:
- - 马戈坑膜的演变在水力学上和船只的演变一样重要.
- 专门的针叶树坑对于保持低流电阻至关重要.
- 没有这些坑,针叶树将面临极大的水力阻力,影响生态系统的生存能力.
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