植物生态学报 ›› 2012, Vol. 36 ›› Issue (2): 159-168.DOI: 10.3724/SP.J.1258.2012.00159

• 研究论文 • 上一篇    下一篇

铜尾矿自然定居白茅对体内氮磷的适时分配及叶片氮磷代谢调节酶活性动态

沈章军1,2, 孙庆业1,*(), 田胜尼3   

  1. 1安徽大学资源与环境工程学院, 合肥 230039
    2合肥师范学院生命科学系, 合肥 230061
    3安徽农业大学生命科学学院, 合肥 230036
  • 收稿日期:2011-09-21 接受日期:2011-11-15 出版日期:2012-09-21 发布日期:2012-02-22
  • 通讯作者: 孙庆业
  • 作者简介:* E-mail: sunqingye@ahu.edu.cn

Dynamics of nitrogen and phosphorus concentrations and nitrate reductase and acidic phosphatase activities in Imperata cylindrica on copper mine tailings

SHEN Zhang-Jun1,2, SUN Qing-Ye1,*(), TIAN Sheng-Ni3   

  1. 1School of Resources and Environment Engineering, Anhui University, Hefei 230039, China
    2School of Life Sciences, Hefei Normal University, Hefei 230061, China
    3School of Life Sciences, Anhui Agricultural University, Hefei 230036, China
  • Received:2011-09-21 Accepted:2011-11-15 Online:2012-09-21 Published:2012-02-22
  • Contact: SUN Qing-Ye

摘要:

白茅(Imperata cylindrica)为铜尾矿废弃地的自然定居优势植物。以农田正常生长的白茅居群为对照, 通过对不同生长时期的白茅体内氮(N)、磷(P)营养浓度, 叶片硝酸还原酶和酸性磷酸酶活性变化等的研究, 探讨铜尾矿胁迫下白茅在营养利用上的生理适应特征。研究结果表明, 在不同的生长时期, 白茅各器官内N、P分配存在一定的差异。在萌芽期, 两居群白茅体内的N、P均主要集中于根状茎。在花蕾期、成熟期时, 两居群白茅体内的N、P均向成熟叶片中迁移, 叶片中N、P浓度均达到最高。但在衰败期时, 铜尾矿居群白茅体内的N主要迁移到根状茎中, P在根状茎中的浓度也达到生长期中的最高值, 而农田居群白茅成熟叶片内N、P浓度依然最高。铜尾矿白茅叶片N、P的再吸收效率分别为49.54%-65.22%和74.71%-98.71%, 而在农田系统中分别为18.18%-52.81%和71.39%-84.07%; 铜尾矿白茅衰老叶片中P达到完全再吸收的程度。铜尾矿白茅叶片硝酸还原酶活性在生长旺盛期显著高于农田居群(p < 0.05), 是白茅加强对自身氮养分代谢活动调节作用的表现; 同一生长时期白茅叶片酸性磷酸酶活性在两种生境间差异性并不明显(p > 0.05), 但随着生长期的延长, 白茅叶片酸性磷酸酶活性表现出不断升高的趋势, 这有利于生长后期衰老叶片中有机P的水解再吸收。可见, 铜尾矿中生长的白茅通过对N、P养分的适时分配, 提高营养成分的再吸收效率, 调节N、P代谢相关调节酶活性的变化方式来减轻铜尾矿生境的营养胁迫。

关键词: 酸性磷酸酶, 铜尾矿, 白茅, 硝酸还原酶, 氮, 养分再吸收率,

Abstract:

Aims Our objective was to study self-regulation of nitrogen (N) and phosphorus (P) nutrient use by Imperata cylindrica at different growth stages on copper mine tailings.
Methods We obtained samples from two different nutrient habitats: copper mine tailings and farmlands. We investigated N and P distributions, N∶P, nutrient resorption rate, nitrate reductase and acidic phosphatase activities in I. cylindrica organs.
Important findings The N and P distributions in I. cylindrica differed by growth period. During the initial stage of growth, N and P in both populations were mainly in the rhizomes. At bud and mature times, N and P concentrations were highest in leaves and lowest in roots and rhizome. At the decay period, N and P concentrations in senescent leaves were (9.19 ± 0.80) and (0.05 ± 0.03) mg·g-1, respectively, which were significantly lower than for the control farmland. The N and P resorption efficiencies of I. cylindrica leaves in the tailings were 49.54%-65.22% and 74.71%-98.71%, respectively, with P in senescent leaves resorbed completely. However, values for the farmland system were 18.18%-52.81% and 71.39%-84.07%, respectively. These results indicated that the poor nutrition condition of the tailings can increase I. cylindrica nutrient resorption efficiency. Nitrate reductase activity of I. cylindrica leaves in the tailings was significantly higher than in the farmlands (p < 0.05); this is useful to regulate I. cylindrica nitrogen metabolism activities. But with plant growth, the differences gradually disappeared. At the same growth period, acidic phosphatase activity of I. cylindrica leaves between the tailings and the farmlands were not significantly significant (p > 0.05). With plant growth, the acidic phosphatase activities increased, which was conducive to decompose organophosphate in senescent leaves and increase P resorption efficiencies.

Key words: acidic phosphatase, copper tailings, Imperata cylindrica, nitrate reductase, nitrogen, nutrient resorption, phosphorus