Growth, water relations, and stomatal development of Caragana korshinskii Kom. and Zygophyllum xanthoxylum (Bunge) Maxim. seedlings in response to water deficits
Growth, water relations, and stomatal development of Caragana korshinskii Kom. and Zygophyllum xanthoxylum (Bunge) Maxim. seedlings in response to water deficits
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DOI：
10.1080/00288230909510503
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发表时间：
2009-06
影响因子：
1.8
通讯作者：
Y. Wu;X. Hu;Y. R. Wang
中科院分区：
文献类型：
--
作者：
Y. Wu;X. Hu;Y. R. Wang
摘要 选择和引进耐旱树种是干旱环境下退化草地恢复的常用方法。本研究调查了在三种浇水方式下，水分胁迫对本土植物 Zygophyllum xanthoxylum (Bunge) Maxim. 和引进物种 Caragana korshinskii Kom. 的生长、水分关系、Na+ 和 K+ 积累以及气孔发育的影响。中度干旱显着降低了科尔欣斯基的黎明前水势、叶片相对含水量、总生物量、总叶面积、地上生物量、叶片总数和比叶面积，但增加了根/总重比（0.23 vs 0.33）。只有严重干旱才会显着影响黄花菜的水分状况和生长。在任何给定的浇水方案中，与 C. korshinskii (0.19 g) 相比，Z. xantoxylum (1.14 g) 的总生物量显着更高。中度干旱显着增加了黄花菜各部分Na+的积累，例如，中度干旱使叶片Na+浓度从1.14增加到2.03 g/100 g DW，然而，当遭受中度干旱时，C. korshinskii叶片中Na+浓度没有变化（0.11与0.12）。 C. korshinskii 和 Z. xanthoxylum 的气孔密度随着可用水量的减少而增加，但两个物种的气孔指数没有差异。中度水分胁迫可显着降低黄花菜的气孔长度、宽度和孔隙宽度，但对科尔沁斯基，需要严重干旱才能产生显着影响。这些结果表明，C. korshinskii 对水分胁迫更敏感，并且表现出很强的表型可塑性，特别是在地上/地下生物量分配方面。相比之下，黄木对水分亏缺的耐受性更强，比叶面积较小，通过渗透调节和气孔关闭维持水分状态的能力较强，从而为应对当地极端干旱环境提供了有效策略。
Abstract The selection and introduction of drought tolerant species is a common method of restoring degraded grasslands in arid environments. This study investigated the effects of water stress on growth, water relations, Na+ and K+ accumulation, and stomatal development in the native plant species Zygophyllum xanthoxylum (Bunge) Maxim., and an introduced species, Caragana korshinskii Kom., under three watering regimes. Moderate drought significantly reduced pre‐dawn water potential, leaf relative water content, total biomass, total leaf area, above‐ground biomass, total number of leaves and specific leaf area, but it increased the root/total weight ratio (0.23 versus 0.33) in C. korshinskii. Only severe drought significantly affected water status and growth in Z. xanthoxylum. In any given watering regime, a significantly higher total biomass was observed in Z. xanthoxylum (1.14 g) compared to C. korshinskii (0.19 g). Moderate drought significantly increased Na+ accumulation in all parts of Z. xanthoxylum, e.g., moderate drought increased leaf Na+ concentration from 1.14 to 2.03 g/100 g DW, however, there was no change in Na+ (0.11 versus 0.12) in the leaf of C. korshinskii when subjected to moderate drought. Stomatal density increased as water availability was reduced in both C. korshinskii and Z. xanthoxylum, but there was no difference in stomatal index of either species. Stomatal length and width, and pore width were significantly reduced by moderate water stress in Z. xanthoxylum, but severe drought was required to produce a significant effect in C. korshinskii. These results indicated that C. korshinskii is more responsive to water stress and exhibits strong phenotypic plasticity especially in above‐ground/below‐ground biomass allocation. In contrast, Z. xanthoxylum was more tolerant to water deficit, with a lower specific leaf area and a strong ability to maintain water status through osmotic adjustment and stomatal closure, thereby providing an effective strategy to cope with local extreme arid environments.