Chin J Plant Ecol ›› 2011, Vol. 35 ›› Issue (2): 214-222.DOI: 10.3724/SP.J.1258.2011.00214

• Research Articles • Previous Articles     Next Articles

Effects of exogenous phenolic acids on nitrate absorption and utilization of hydroponic cuttings of Populus × euramericana ‘Neva’

WANG Hua-Tian1,*(), YANG Yang1, WANG Yan-Ping1, JIANG Yue-Zhong2, WANG Zong-Qin1   

  1. 1Key Laboratory of Agricultural Ecology and Environment of Shandong Agricultural University, Forestry College of Shandong Agricultural University, Tai’an, Shandong 271018, China
    2Shandong Academy of Forestry, Jinan 250014, China
  • Received:2010-01-04 Accepted:2010-11-01 Online:2011-02-01 Published:2011-01-21

Abstract:

Aims Degradation of forestland productivity by continuously cropped poplar plantations is closely related to phenolic acid accumulation in the soil. Soil nitrogen is an essential factor affecting the growth and development of poplars. Nitrate was one of the main forms of nitrogen in soil, and the impact of phenolic acids on absorption and utilization of nitrate is vital to revealing the allelopathic mechanism of phenolic acids and proposing measures for improving forestland productivity.
Methods We cultured hydroponic cuttings of black poplar cultivar ‘I-107’ (Populus × euramericana ‘Neva’) in improved Hoagland nutrient solution to which we added gradations of phenolic acids (0, 0.5X, 1.0X, 1.5X, 2.0X) according to actual content (1.0X) in the soil of a second-generation poplar plantation. We observed the effects of phenolic acids on nitrate absorption and utilization by the hydroponic cuttings. We tested several physiological characteristics closely related to nitrate absorption and utilization at 1, 5, 10, 20, 30 and 40 days after treatment with phenolic acids.
Important findings Degree of root injury was aggravated by phenolic acids, root activity was inhibited by phenolic acids and both indexes of phenolic acid treatments were significantly different from the control at 40th day (p < 0.05). Absorption of nitrate by poplar hydroponic cuttings was significantly diminished by phenolic acids at 48 h (p < 0.05). Low levels of phenolic acids (0.5X and 1.0X) led to accumulation of nitrate in cuttings, but high levels (1.5X and 2.0X) led to decline in nitrate content. Nitrate activity of poplar hydroponic cuttings was inhibited by phenolic acids, and treatment values were significantly different from the control at 40th day (p < 0.05). Nitrate content increased in later periods with phenolic acids treatments. Relationship of effects of phenolic acids concentration and duration time on nitrate metabolism could be described by multiple linear regression.

Key words: absorption, allelopathy, nitrate nitrogen, phenolic acids, poplar