Chin J Plant Ecol ›› 2011, Vol. 35 ›› Issue (5): 523-530.DOI: 10.3724/SP.J.1258.2011.00523

• Research Articles • Previous Articles     Next Articles

Nitrogen supply mitigates the effects of elevated [O3] on photosynthesis and yield in wheat

CHEN Juan1,2, ZENG Qing1,*(), ZHU Jian-Guo1, LIU Gang1, CAO Ji-Ling1,2, XIE Zu-Bin1, TANG Hao-Ye1, KAZUHIKO Kobayashi3   

  1. 1State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China
    2Graduate University of Chinese Academy of Sciences, Beijing 100049, China
    3Department of Global Agricultural Sciences, Graduate School of Agricultural and Life Sciences, the University of Tokyo, Tokyo 113-8657, Japan
  • Received:2010-07-23 Accepted:2011-01-21 Online:2011-07-23 Published:2011-06-07
  • Contact: ZENG Qing

Abstract:

Aims Our objective was to study the interactive influences of ozone (O3) and nitrogen (N) on photosynthesis and yield in winter wheat (Triticum aestivum).

Methods The winter wheat was exposed to two levels of O3 (ambient and 1.5 ambient) and two levels of N supply (210 and 250 kg·hm-2) under field conditions.

Important findings O3 exposure significantly reduced the net photosynthetic rate (Pn), stomatal conductance (Gs) and transpiration rate (Tr) of wheat leaves in the filling stage by 28.95%, 31.79 % and 23.17%, respectively. O3 exposure also significantly reduced the content of chlorophyll a (Chl a), chlorophyll b (Chl b), carotene (Car), total chlorophyll (Chl t) and soluble protein in the filling stage by 58.89%, 68.64%, 22.89%, 60.31% and 32.00%, respectively, while intercellular CO2 concentration (Ci) changed slightly. Biomass in the maturing stage and yield of the wheat were also reduced by elevated O3 by 12.23% and 12.63%, respectively. High N availability significantly increased Pn, Chl a, Chl b, soluble protein, biomass and yield of the wheat leaves by 25.66%, 83.05%, 121.57%, 30.33%, 14.94% and 10.67%, respectively, while Gs, Ci, Tr and Car were influenced slightly by high N, which indicated that the increase of Pn was mainly caused by the increment of Chl a, Chl b and soluble protein. The interactive effects of O3 and N on the concentrations of Pn, Chl a, Chl b and soluble protein were significant. These results suggest that sufficient N supply can modify the effects of elevated O3 on photosynthesis and yield in wheat.

Key words: biomass, mediation, nitrogen, ozone, photosynthesis, yield