Chin J Plant Ecol ›› 2013, Vol. 37 ›› Issue (7): 650-655.DOI: 10.3724/SP.J.1258.2013.00067

• Research Articles • Previous Articles     Next Articles

Applicability of modified exponential model in photosynthetic-CO2 response curve of barley

LUO Fu-Yan1,*(),CHEN Wei-Ying1,2,*(),CHEN Zhen-Yong1   

  1. 1Key Laboratory of Southwest China Wildlife Resources Conservation, College of Life Science, China West Normal University, Nanchong, Sichuan 637009, China
    2Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, China
  • Received:2013-01-11 Accepted:2013-05-20 Online:2013-07-01 Published:2013-07-05

Abstract:

Aims The photosynthetic-CO2 response curve is an important tool for understanding the response of plants to CO2. Common models of photosynthetic-CO2 response curve can not calculate the max net photosynthetic rate accurately. In our study, we used a new model called the modified exponential model to simulate the relationship between net photosynthetic rate and CO2 concentration of barley. We then compared the differences and accuracies with the modified rectangular hyperbola model, rectangular hyperbola model, nonrectangular hyperbola model and exponential model. Our objectives were to test the merit and precision of these models and provide reference for selecting the best models for the photosynthetic-CO2 response curves of plants.
Methods The CO2-response curves of Tibetan hulless barley were recorded with an infrared gas analyzer system (LI-6400). The measured data were used to simulate and test the precision of the models. Mean square error (MSE) and mean absolute error (MAE) were used to evaluate the precision of the models. Some predicted physiological parameters of the four models were compared with the measured values.
Important findings The photosynthetic-CO2 response curves of barley were best described by the modified exponential model. The CO2 saturation point and maximum net photosynthetic rate of barley obtained by the modified exponential model were 25.9 μmol CO2∙m-2∙s-1 and 484 μmol∙mol-1, respectively.

Key words: Hordeum vulgare, modified exponential model, photosynthetic capacity, photosynthetic-CO2 response curve, saturation CO2 concentration