Comparative study on photosynthesis of medicinal plant Saposhnikovia divaricata in different periods

作者 HAN Zhong-Ming; WANG Yun-He; HAN Mei; YANG Li-Min

期刊 Acta Ecologica Sinica , 2009,3:29

摘要 The diurnal changes in net photosynthetic rate (P_n) of Saposhnikovia divaricata (Turcz. ) Schischk. and their relationships with photosynthetic active radiation ( PAR), atmospheric CO_2 concentration ( C_a), ambient temperature ( T_a) , leaf temperature ( T_1,) and relative humidity ( RH) were studied systematically in different periods. This knowledge is essential for formulating generalization regarding the cultivation of the species in Jilin Province. Results showed that the diurnal changes in P_n of the species in different periods were similar and could be expressed as two-hump curves, reflecting a significant middy depression. The decrease in P_n during midday was mainly resulted from non-stomatal limitation in July, but stomatal limitation occurred in August and September. High temperature and low relative humidity were critical factors constraining P_n in July. The non - synchronous change of P_n and E were the main reason leading the variations of WUE. PAR affected P_n, synthesis and transformation of organic matter, which restricted the production for S. divaricata. There was a significantly and positively correlation between the P_n and PAR ( P < 0. 05 ) . The responses of S. divaricata leaves to the environmental factors were different during growing season, and the direct effects of environmental factors in three different months were of the order: T_a. > PAR > T_1 > C_a > RH in July, T_1 > PAR > T_a > RH > C_a in August, T_a > PAR > T_1 > C_a > RH in September.

涉及物种 防风 Saposhnikovia divaricata