A modified rectangular hyperbola to describe the light-response curve of photosynthesis of Bidens pilosa L. grown under low and high light conditions

• Published in: Frontiers of agriculture in China Vol. 4; no. 1; pp. 50 - 55
• Main Authors: Ye, Zipiao, Zhao, Zehai
• Format: Journal Article
• Language: English
• Published: Heidelberg SP Higher Education Press 01.03.2010; Higher Education Press Limited Company
• Subjects: Agriculture; Biomedical and Life Sciences; Carbon dioxide; Humidity; Hypotheses; Leaves; Life Sciences; Light; Light intensity; Photochemicals; Photosynthesis; Plant biology; Plant sciences; Radiation; Research Article; Respiration; Seeds; Studies; Sunlight; China; initial slope; light-saturated net photosynthetic rate; saturation light intensity; apparent quantum yield
• ISSN: 1673-7334; 1673-744X
• DOI: 10.1007/s11703-009-0092-0

The light-response curve of leaf net photosynthesis is an important tool for understanding the photochemical efficiency of the photosynthetic process. We measured the light-response of the photosynthetic rate of Bidens pilosa L., when grown under high light of 100% full sunlight (HL) and low light of 50% full sunlight (LL) using a gas analyzer Li-6400. The measured data were simulated by a modified rectangular hyperbola. The fitted results showed that the modified rectangular hyperbola described the part of the curve up to the light saturation and the range of levels above the saturation light intensity in Bidens pilosa L. well. It was used to directly calculate the main photosynthetic parameters, including the lightsaturated net photosynthetic rate ( P max ), saturation light intensity ( I m ), light compensation point ( I c ), dark respiration rate, and the initial slope of curve without any additional hypotheses. Good agreement was obtained between the modified rectangular hyperbola estimates and observations of P max and I m of B. pilosa under LH and LL conditions. Furthermore, the modified rectangular hyperbola provided a very easy and simple method for simultaneously simulating the data on the light-response curve of photosynthesis at low irradiances, saturating irradiances, photoacclimation and photoinhibition.