Key Laboratory of Mountain Environmental Change and Regulation, Chengdu Institute of Mountain Hazards and Environment, The Alpine Ecosystem Observation and Experiment Station of the Gongga Mountain, Chinese Academy of Sciences & Ministry of Water Conservancy, Chengdu 610041, P.R. China.
Physiol Plant. 2010 Aug 1;139(4):335-47. doi: 10.1111/j.1399-3054.2010.01370.x. Epub 2010 Mar 8.
Abies fabri (Mast.) Craib. (A. fabri) is an endemic and dominant species in typical subalpine dark coniferous forests distributed in mountainous regions of Western Sichuan, China. We investigated the ecophysiological responses of A. fabri seedlings to short-term experimental drought, nitrogen supply and their interaction. Drought stress was created by excluding natural precipitation with automatically controlled plastic roof that covered the seedlings. Nitrogen fertilization was applied weekly by spraying over seedlings ammonium nitrate solution (50 kg N ha(-1) year(-1)) during the growing season of 2009. The results showed that drought stress decreased leaf relative water content (RWC), whereas it caused marked increases in root mass ratio (RMR) and root/shoot mass ratio by 6.19 and 10.39%, respectively, as compared with the control. Drought stress increased malondialdehyde (MDA) content, electrolyte leakage, proline content, soluble sugars content and the activities of antioxidant enzymes, whereas nitrogen supply decreased MDA content, but enhanced activities of some antioxidant enzymes [especially peroxidase (POD)]. In the drought stressed plots, nitrogen supply increased RWC and decreased the content of MDA. The combination of drought stress and nitrogen supply also decreased the activities of antioxidant enzymes. These results indicated that the negative effects of drought stress on A. fabri seedlings might be alleviated by nitrogen supply.
巴山冷杉（Mast.）Craib.（A. fabri）是中国川西山区典型亚高山暗针叶林中的特有种和优势种。本研究调查了巴山冷杉幼苗对短期实验干旱、氮供应及其互作的生理生态响应。通过自动控制的塑料屋顶排除自然降水来创造干旱胁迫，该屋顶覆盖着幼苗。在 2009 年生长季节，每周通过向幼苗喷洒硝酸铵溶液（50kg Nha(-1)year(-1))进行氮施肥。结果表明，与对照相比，干旱胁迫降低了叶片相对含水量（RWC），但分别使根质量比（RMR）和根/茎质量比显著增加了 6.19%和 10.39%。干旱胁迫增加了丙二醛（MDA）含量、电解质渗漏、脯氨酸含量、可溶性糖含量和抗氧化酶活性，而氮供应降低了 MDA 含量，但增强了一些抗氧化酶的活性[特别是过氧化物酶（POD）]。在干旱胁迫的样地中，氮供应增加了 RWC，降低了 MDA 含量。干旱胁迫和氮供应的组合也降低了抗氧化酶的活性。这些结果表明，氮供应可能缓解了干旱胁迫对巴山冷杉幼苗的负面影响。
