Abstract

Info

Title:: Diurnal Variation of Photosynthesis in Leaves of Dryopteris fragrans L.Schott

Author(s):: LIANG Yantao1; CHEN Lingling2; XU Taihai1; ZHANG Guofa1; ZHAO Xiaoju1; CHANG Ying2; (1.Life Science Department，Daqing Normal Univcrsity,Daqing,Heilongjiang 163712;2.College of Life Scicnces，Northeast Agricultural University,Harbin,Heilongjiang 150030)

Abstract:: Dryopteris fragrans was used as test material,the photosynthesis process and light response of wild Dryopteris fragrans L.Schott were studied by LCi portable photosynthesis apparatus.The results showed that under natural conditions，the curve of net photosynthetic rate of Dryopteris fragrans leaves（Pn） in sunny days in summer was of single peak type;the photosynthetic efficiency was higher at noon,it was up to 3.09 μmol·m-2·s-1,and then decreased significantly.It suggested that Dryopteris fragrans was resistant to intense light and high-temperature.However,the closure of stomata and photosynthetic activity of mesophyll cells were influenced by environmental factors.Photoinhibition induced by intense light was the main reason for the significantly decreased photosynthetic efficiency of Dryopteris fragrans leaf after noon.It showed that the correlation coefficient of Pn and environmental photosynthetic effective radiation (PARe) was 0.979,and the direct path coefficient of air temperature (Ta) was 1.926,indicating that PARe and Ta were the main factors affecting the diurnal change of net photosynthetic rate of the leaves of Dryopteris fragrans.