Chin J Plant Ecol ›› 2023, Vol. 47 ›› Issue (3): 348-360.DOI: 10.17521/cjpe.2022.0201

Special Issue: 光合作用

• Research Articles • Previous Articles     Next Articles

Effects of different nitrogen forms on photosynthesis characteristics and growth of poplar

DU Ying-Dong, YUAN Xiang-Yang(), FENG Zhao-Zhong   

  1. Key Laboratory of Ecosystem Carbon Source and Sink, China Meteorological Administration (ECSS-CMA), School of Applied Meteorology, Nanjing University of Information Science & Technology, Nanjing 210044, China
  • Received:2022-05-18 Accepted:2022-09-28 Online:2023-03-20 Published:2022-09-28
  • Contact: YUAN Xiang-Yang
  • Supported by:
    International (Regional) Cooperation and Exchanges Project of NSFC(42061160479)


Aims Poplars (Populusspp.) are main timber and greening trees in the Northern Plains of China, and remains unclear whether nitrogen form defines the effects of nitrogen on poplar growth and physiology. Hence, this study aimed at investigating the effects of different nitrogen forms (ammonium nitrogen, nitrate nitrogen, ammonia-nitrogen mixed state and amido nitrogen) on photosynthesis and growth of poplar seedlings.

Methods Two poplar clones (Populus deltoides cv. ‘55/56’ × P. deltoides cv. ‘Imperial’, clone ‘546’ and P. euramericana cv. ‘74/76’, clone ‘107’) were used as test materials. Poplar ‘546’ has lower plant height and larger single leaf area and is more sensitive to low temperature than poplar ‘107’. An experiment was conducted to determine gas exchange, chlorophyll fluorescence, plant height and branch diameter, specific leaf area, biomass and root-shoot ratio in seedlings treated with different forms of nitrogen.

Important findings The results showed that leaf photosynthesis characteristics of clones ‘546’ and ‘107’ were similar, but their growth parameters differed. Nitrogen application significantly increased leaf net photosynthetic rate, stomatal conductance, electron transport rate of photosystem II (PSII), PSII actual photochemical quantum yield, photosynthetic electron transport rate, branch diameter, plant height, specific leaf area and plant biomass, but reduced root-shoot ratio. Except for leaf net photosynthetic rate, there were no significant differences in other photosynthesis characteristics and growth parameters among different nitrogen forms. The response significantly differed between the two clones. Relative to other nitrogen treatments, specifically, leaf net photosynthetic rate was significantly increased by ammonia-nitrogen mixed state treatment in clone ‘107’, while most of the indexes of ‘546’ poplar were not significantly different among different nitrogen treatments. These results suggested that the application of ammonia-nitrogen mixed state and amido nitrogen can promote the photosynthesis, growth and biomass accumulation of poplar seedlings. However, clone ‘107’ has a higher nitrogen use efficiency under amide nitrogen treatment, whereas the best suitable nitrogen application form for clone ‘546’ was nitrate nitrogen and ammonium nitrogen.

Key words: poplar, nitrogen form, biomass, gas exchange parameter, fluorescence parameter