Photosynthetica

, Volume 48, Issue 3, pp 389–399

Effects of enhanced atmospheric ammonia on photosynthetic characteristics of two maize (Zea mays L.) cultivars with various nitrogen supply across long-term growth period and their diurnal change patterns

Original Papers

DOI: 10.1007/s11099-010-0051-2

Cite this article as:
Zhang, L.X., Qiang, H., Li, S.Q. et al. Photosynthetica (2010) 48: 389. doi:10.1007/s11099-010-0051-2

Abstract

We investigated the effect of enhanced atmospheric ammonia (NH3) in combination with low and high nitrogen (LN and HN, respectively) growth medium on photosynthetic characteristics of two maize (Zea mays L.) cultivars (NE5 with high- and SD19 with low N-use efficiency) across long-term growth period and their diurnal change patterns exposed to 10 nl l−1 and 1,000 nl l−1 NH3 fumigation in open-top chambers (OTCs). Regardless of the level of N in medium, increased NH3 concentration promoted maximum net photosynthetic rate (Pmax) and apparent quantum yield (AQY) of both cultivars at earlier growth stages, but inhibited Pmax of NE5 from silking to maturity stage and that of SD19 at maturity stage only above the ambient concentration. Greater positive/less negative responses were predominant in the LN than in the HN treatment, especially for SD19. Dark respiration rate (RD) remained more enhanced in the LN than in the HN treatment for SD19 as well as increased in the LN while decreased in the HN treatment for NE5 at their silking stage, following exposure to elevated NH3 concentration. Additionally, enhanced atmospheric NH3 increased net photosynthetic rate (PN) and stomatal conductance (gs) but reduced intercellular CO2 concentration (Ci) of both cultivars with either the LN or HN treatment during the diurnal period at tasseling stage. The diurnal change patterns of PN and gs showed bimodal curve type and those of Ci presented single W-curve type for NE5, when NH3 concentration was enhanced. As for SD19, single-peak curve type was showed for both PN and gs while single V-curve type for Ci. All results supported the hypothesis that appropriately enhanced atmospheric NH3 can increase assimilation of CO2 by improving photosynthesis of maize plant, especially at earlier growth stages and after photosynthetic “noon-break” point. These impacts of elevated NH3 concentration were more beneficial for SD19 as compared to those for NE5, especially in the LN supply environment.

Additional key words

atmospheric ammoniadiurnal time coursemaizenitrogen supplyphotosynthetic parameters

Abbreviations

AQY

apparent quantum yield

Ci

intercellular CO2 concentration

gs

stomatal conductance

HN

high nitrogen

LN

low nitrogen

OTCs

open-top chambers

PAR

photosynthetically active radiation

Pmax

net maximum photosynthetic rate

PN

net photosynthetic rate

RD

dark respiration rate

RH

relative humidity

Rubisco

ribulose-1,5-bisphosphate carboxylase/oxygenase

Copyright information

© Springer Science+Business Media B.V. 2010

Authors and Affiliations

  • L. X. Zhang
    • 1
    • 2
  • H. Qiang
    • 2
    • 3
  • S. Q. Li
    • 1
    • 2
    • 3
  • X. L. Chen
    • 2
    • 3
  1. 1.State Key Laboratory of Soil Erosion and Dryland Farming and College of Life SciencesNorthwest A & F UniversityYangling, ShaanxiP.R. China
  2. 2.State Key Laboratory of Soil Erosion and Dryland Farming, Institute of Soil and Water ConservationNorthwest A & F University and Chinese Academy of SciencesYangling, ShaanxiP.R. China
  3. 3.College of Resource and EnvironmentNorthwest A & F UniversityYangling, ShaanxiP. R. China