Response of Chlorophyll Fluorescence Characteristics to Degraded Wetlands in the Leaves of Carex lasiocarpa, C. pseudocuraica and Deyeuxia angustifolia in the Wetland of Jilin Province, China

摘要

In this study, the changes in the function of photosystem II (PSII) in three dominant wetland plants as experimental materials under degraded wetlands were analyzed using chlorophyll fluorescence techniques. Leaf samples from three typical wetland plants, Carex lasiocarpa, C. pseudocuraica and Deyeuxia angustifolia in the Jilin Province wetland, China were used. The results showed that the net photosynthetic rate (P n ), transpiration rate (T r ) and stomatal conductance (G s ) of C. pseudocuraica and D. angustifolia were more higher significantly than C. lasiocarpa, and in intercellular CO 2 concentration (C i ) there was no significant difference. In addition, compared with C. pseudocuraica, C. pseudocuraica and D. angustifolia had higher photosynthetic performance index (PI ABS ) and PSII photochemical efficiency (F v /F m ) based on absorption of light energy, indicating that the PSII photochemical activity of C. pseudocuraica and D. angustifolia is significantly higher than that of C. lasiocarpa. By standardizing the OJIP curve of leaves three dominant species in degraded wet ground, it can be found that the activity of oxygen evolving complex (OEC) on the donor side of PSII increased, and the electron transfer on the receptor side of PSII was significantly higher than that of C. lasiocarpa. The actual photochemical efficiency (Ф PS II ) and electron transfer rate (ETR) of C. pseudocuraica and D. angustifolia were also significantly higher than C. lasiocarpa under higher light intensity. In addition, through the utilization of PSII light energy, it can be found that the proportion of absorption of light energy dissipation in the form of invalid heat energy and the proportion of its distribution to the inactivation reaction center are reduced, while the absorption light energy was more used in the photochemical reaction center to improve its photochemical function. There was no significant difference in PSII function between the degraded wetland and the leaves of C. pseudocuraica and D. angustifolia, which indicated that the photosynthetic PSII function of C. pseudocuraica and D. angustifolia had strong adaptability to wetland degradation.