Chin J Plant Ecol ›› 2013, Vol. 37 ›› Issue (2): 122-131.DOI: 10.3724/SP.J.1258.2013.00013

• Research Articles • Previous Articles     Next Articles

Effects of nitrogen regulation on photosystem II chlorophyll fluorescence characteristics of functional leaves in sugar beet (Beta vulgaris) under salt environment

YIN Hai-Long1,2,3,*(), TIAN Chang-Yan1,3,**()   

  1. 1Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, ürümqi 830011, China
    2University of Chinese Academy of Sciences, Beijing 100049, China
    3State Key Laboratory of Oasis Ecology and Desert Environment, ürümqi 830011, China
  • Received:2012-11-08 Accepted:2012-12-10 Online:2013-11-08 Published:2013-01-31
  • Contact: TIAN Chang-Yan

Abstract:

Aims Our objective was to determine the effects of nitrogen regulation on photosystem II (PSII) chlorophyll fluorescence of functional leaves in sugar beet (Beta vulgaris) under salt environment.
Methods Using potted sugar beet plants, different salt environments were produced with NaCl; nitrogen was produced with NH4NO3.
Important findings Maximal PSII quantum yield (Fv/Fm), and latent PSII quantum yield (Fv/Fo), effective PSII quantum yield (Y(II)), quantum yield of non-regulated energy dissipation (Y(NO)), electron transport rate (ETR) and coefficient of photochemical quenching (qP) were increased by nitrogen application under mild, moderate and high salt environments, and these parameters increased with increased nitrogen application. The results of rapid light-response curves of chlorophyll fluorescence parameters showed that quantum yield of regulated energy dissipation (Y(NPQ)), ETR and coefficient of nonphotochemical quenching (NPQ) increased with the increase of light intensity under every treatment. By contrast, Y(II), Y(NO) and qP decreased with increased light intensity. Openness of PSII reaction centers of functional leaves in sugar beet were also improved in range of effective intensity (0-1000 μmol·m-2·s-1) by nitrogen application, and PSII was adjusted to dissipate excess photon energy to protect the PSII reaction centers. Application of nitrogen could also increase the content of chlorophyll, carotenoid and ratio of chlorophyll a to chlorophyll b, and the content of chlorophyll and carotenoid were increased with the increase of nitrogen application under every salt environment. These results indicated that PSII activity and light-use efficiency could be improved by nitrogen application, and then the adaptability of sugar beet to salt environment was strengthened.

Key words: Beta vulgaris, chlorophyll fluorescence, nitrogen, photosynthetic pigments, salinity