Divergences in hydraulic architecture form an important basis for niche differentiation between diploid and polyploid Betula species in NE China
Divergences in hydraulic architecture form an important basis for niche differentiation between diploid and polyploid Betula species in NE China
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水力结构的差异是中国东北地区二倍体和多倍体桦树物种生态位分化的重要基础
DOI：
10.1093/treephys/tpx004
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发表时间：
2017-05
期刊：
影响因子：
4
通讯作者：
Guang-You Hao
中科院分区：
文献类型：
--
作者：
Wei-Wei Zhang;Jia Song;Miao Wang;Yan-Yan Liu;Na Li;Yong-Jiang Zhang;N. Michele Holbrook;Guang-You Hao
多倍体和二倍体植物之间的栖息地分化经常被观察到，多倍体通常占据更多的压力环境。在木本植物中，多倍体化可以极大地影响木材的特性，但它对木质部水力学的影响的知识很少。东北桦属4个种，代表2个二倍体和2个多倍体，具有明显的生境分化，为从木质部水力学角度研究树木多倍体化对环境适应的影响提供了一个独特的研究体系。为了验证这一假设，水力结构的变化在确定其生态位分化中发挥了重要作用，我们测量了木材结构性状在组织和坑水平和量化木质部水分运输效率和安全性在这些物种。两个多倍体的平均导管直径（45.1和45.5 μm）显著大于两个二倍体（25.9和24.5 μm），尽管多倍体占据了更多的胁迫环境。如对应于茎导水率损失50%的负水势所示，尽管两个多倍体的导管直径较大，但其对干旱诱导的栓塞的抗性显著高于两个二倍体（-5.23和-5.05vs-3.86和-3.13MPa）。这似乎是不一致的调和不同的特点，有利于更大的栓塞阻力在坑的水平在两个多倍体物种。我们的研究结果清楚地表明，这两个多倍体物种有显着不同的坑级解剖特征，有利于更大的水力安全比他们的同源二倍体物种，这可能有助于丰富的多倍体桦树在更紧张的栖息地，然而，较少的孔间导管坑减少叶边材面积可能会损害他们的竞争力在更有利的条件下。长白山白桦属植物二倍体和多倍体的水力结构差异是其生境沿着环境梯度明显分化的重要功能基础。
Habitat differentiation between polyploid and diploid plants are frequently observed, with polyploids usually occupying more stressed environments. In woody plants, polyploidization can greatly affect wood characteristics but knowledge of its influences on xylem hydraulics is scarce. The four Betula species in NE China, representing two diploids and two polyploids with obvious habitat differentiation, provide an exceptional study system for investigating the impact of polyploidization on environmental adaptation of trees from the point view of xylem hydraulics. To test the hypothesis that changes in hydraulic architecture play an important role in determining their niche differentiation, we measured wood structural traits at both the tissue and pit levels and quantified xylem water transport efficiency and safety in these species. The two polyploids had significantly larger hydraulic weighted mean vessel diameters than the two diploids (45.1 and 45.5 vs 25.9 and 24.5 μm) although the polyploids are occupying more stressed environments. As indicated by more negative water potentials corresponding to 50% loss of stem hydraulic conductivities, the two polyploids exhibited significantly higher resistance to drought-induced embolism than the two diploids (-5.23 and -5.05 vs -3.86 and -3.13 MPa) despite their larger vessel diameters. This seeming discrepancy is reconciled by distinct characteristics favoring greater embolism resistance at the pit level in the two polyploid species. Our results showed clearly that the two polyploid species have remarkably different pit-level anatomical traits favoring greater hydraulic safety than their congeneric diploid species, which have likely contributed to the abundance of polyploid birches in more stressed habitats; however, less porous inter-conduit pits together with a reduced leaf to sapwood area may have compromised their competitiveness under more favorable conditions. Contrasts in hydraulic architecture between diploid and polyploid Betula species suggest an important functional basis for their clear habitat differentiation along environmental gradients in Changbai Mountain of NE China.
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影响因子：
7.3
作者：
Markesteijn, Lars;Poorter, Lourens;Bongers, Frans
通讯作者：
Bongers, Frans
影响因子：
7.4
作者：
Yong-Jiang Zhang;F. E. Rockwell;James K. Wheeler;N. Holbrook
通讯作者：
Yong-Jiang Zhang;F. E. Rockwell;James K. Wheeler;N. Holbrook
影响因子：
6.9
作者：
Zufferey V;Cochard H;Ameglio T;Spring JL;Viret O
通讯作者：
Viret O
DOI：
10.1111/j.1469-8137.2011.03988.x
发表时间：
2012-02
期刊：
The New phytologist
影响因子：
--
作者：
Manzaneda AJ;Rey PJ;Bastida JM;Weiss-Lehman C;Raskin E;Mitchell-Olds T
通讯作者：
Mitchell-Olds T
DOI：
10.1007/978-3-662-22627-8
发表时间：
1983-06
期刊：
--
影响因子：
--
作者：
M. Zimmermann
通讯作者：
M. Zimmermann