植物生态学报 ›› 2014, Vol. 38 ›› Issue (12): 1345-1355.DOI: 10.3724/SP.J.1258.2014.00129

• 研究论文 • 上一篇    下一篇

磷元素和土壤酸化交互作用对核桃幼苗光合特性的影响

张翠萍1, 孟平2, 李建中3, 万贤崇1,*()   

  1. 1中国林业科学研究院新技术研究所, 北京 100091
    2中国林业科学研究院林业研究所, 国家林业局林木培育重点试验室, 北京 100091
    3济源市国有大沟河林场, 河南济源 454650
  • 收稿日期:2014-04-03 接受日期:2014-08-18 出版日期:2014-04-03 发布日期:2015-04-16
  • 通讯作者: 万贤崇
  • 作者简介:* (E-mail: wxc@caf.ac.cn)

Interactive effects of soil acidification and phosphorus deficiency on photosynthetic characteristics and growth in Juglans regia seedlings

ZHANG Cui-Ping1, MENG Ping2, LI Jian-Zhong3, WAN Xian-Chong1,*()   

  1. 1Institute of New Forestry Technology, Chinese Academy of Forestry, Beijing 100091, China
    2Institute of Forestry, Chinese Academy of Forestry, Key Laboratory of Tree Breeding and Cultivation, State Forestry Administration, Beijing 100091, China
    3Dagouhe National Forest Farm, Jiyuan, Henan 454650, China
  • Received:2014-04-03 Accepted:2014-08-18 Online:2014-04-03 Published:2015-04-16
  • Contact: WAN Xian-Chong

摘要:

核桃(Juglans regia)向南推广种植不可避免地会遇到土壤酸化和缺磷的环境, 这种环境如何影响核桃的生长是生产中需要知晓的基础问题。该文研究了土壤不同pH值对核桃的磷素营养影响以及缺磷对核桃幼苗水分平衡、光合特性和生长的影响。在温室内采用砂培盆栽试验, 研究一年生核桃嫁接幼苗在不同pH值、磷水平基质中的水分关系、光合特性和生长的应对机制。研究设4种处理, 即: 对照(正常供应磷素+ pH 6.0); 正常供应磷素+ pH 3.0; 不添加磷素+ pH 6.0; 不添加磷素+ pH 3.0。结果显示: pH值与磷素对核桃幼苗的影响是两个相互独立的过程, 酸性(pH值3.0)条件下, 核桃幼苗根系生物量降低、根冠比减小, 根系导水率降低, 对磷素的吸收利用减少, 尽管其供磷正常, 但各生长指标及生理指标与磷胁迫条件下反应相似; 两因素具有一定的叠加性, 在磷胁迫条件下, 酸化(pH值3.0)对核桃幼苗的损害进一步加剧。各指标具体变化如下: 酸化及磷胁迫条件下核桃根系水分导度降低, 叶柄木质部结构改变, 导管密度降低, 木质部导管栓塞程度增加, 叶柄导水率下降, 植株水分运输效率降低, 叶片水势降低, 诱导气孔关闭; 气孔导度降低, 光合作用能力下降; 胁迫条件下, 叶绿素荧光参数最大光化学效率低于0.8, 实际光化学效率、光化学淬灭下降, 非光化学淬灭增加, 核桃幼苗受胁迫环境损害, 叶片光系统II光合电子传递活性受到抑制, 光合能力下降。总之, 土壤酸化抑制了核桃幼苗对磷元素的吸收利用, 造成体内缺磷; 磷胁迫及酸化抑制了叶柄木质部的发育, 降低了根系水分导度和叶柄导水率, 干扰了核桃幼苗水分平衡, 通过气孔与非气孔共同调节, 限制了核桃幼苗光合作用, 抑制了核桃幼苗高生长、直径生长及叶面积增加; 但并没有发现土壤酸化和缺磷之间有明显的交互作用。

关键词: 生长, 水力学特性, 核桃, pH值, 磷素营养, 光合特性

Abstract:

AimsOur main purposes were to explore effects of phosphorus deficiency and soil acidification on growth, water balance and phosphorus nutrition in Juglans regia seedlings and to investigate the hydraulic mechanism involved in reduced photosynthesis and growth.

Methods We measured growth, hydraulic characteristics, and gas exchanges in J. regia seedlings. The effects of phosphorus deficiency and soil acidification on xylem anatomic structure, water balance and photosynthetic characteristics were also analyzed.

Important findings Soil acidification inhibited the phosphorous uptake and utilization efficiency in J. regia seedlings. A combination of soil acidification and phosphorous deficiency interrupted water balance, and reduced photosynthesis and growth of J. regia seedlings. Under soil acidification and phosphorus deficiency, non-stomatal factors also played a role in inhibiting photosynthesis.

Key words: growth, hydraulic conductance, Juglans regia, pH value, phosphorus nutrition, photosynthetic characteristics