Study On Photosynthesis And Chlorophyll Fluorescence Of Three Ericaceae Species In Daxing'an Mountains

Photosynthetic and fluorescence measurements,as an important way to study plant growth characteristics,are of great significance to clarify its special living environment.This experiment used portable photosynthetic apparatus(CIRAS-3)and convenient chlorophyll fluorescence imager(Handy Flour Cam)to measure the photosynthetic parameters and chlorophyll fluorescence parameters of Rhododendron dauricum,Vaccinium uliginosum and Vaccinium vitis-idaea to understand the dynamic changes of photosynthesis and fluorescenc,and to explore the main meteorological factors affecting their photosynthesis,the purpose is to provide data support for the rational management of Daxing'an Mountains forest.The results show that:(1)The diurnal variation of Rhododendron dauricum net photosynthetic rate Pn presents a single-peak curve,Vaccinium uliginosum and Vaccinium vitis-idaea change to show unimodal and bimodal curves Pn day.The Rhododendron dauricum Pn peak at 10:00,At 10:00,Pn main peaks of Vaccinium uliginosum and Vaccinium vitis-idaea,The secondary peak appears at 14:00.A local"V"curve"was observed in the variation of Rhododendron dauricum,Vaccinium uliginosum and Vaccinium vitis-idaea.A maximum of Rhododendron dauricum and Vaccinium uliginosum Pn in July 21,And the maximum value Pn Vaccinium vitis-idaea,4.59,4.49,4.66?mol m^-2s^-1respectively.(2)The Rhododendron dauricum,Vaccinium uliginosum and Vaccinium vitis-idaea dark adaptation time are 15 min?15min and 20 min;The fluorescence response curve showed that the resistance of Vaccinium in Ericaceae was stronger than that of Rhododendron in Ericaceae,There is a wider range of light adaptation.The maximum;The photochemical efficiency qP?three phytochemical quenching Fv/Fm?the"V"type"of the daily variation trend of the actual photon yield Y(?)?potential of photoactivity Rhododendron dauricum,Vaccinium uliginosum,Vaccinium vitis-idaea,Change trend of non-photochemical quenching NPQ showed single peak curve.The monthly variation curve of Fv/Fm of Rhododendron dauricum,Vaccinium uliginosum,Vaccinium vitis-idaea are irregular.(3)There was significant correlation between the Fv/Fm?Fv/Fo?Y(?)?qP?NPQ of Rhododendron dauricum,Vaccinium uliginosum,Vaccinium vitis-idaea and meteorological factors such as photosynthetically active radiation PAR,the correlation between Pn and PAR,other photosynthetic parameters are inconsistent with the environmental factors correlationand,The above shows that the environmental factors have a greater influence on the fluorescence properties of the three plants.To sum up,Vaccinium vitis-idaea has a strong ability to regulate light intensity,high efficiency of light energy utilization,can provide more light energy for photochemical reaction,and can produce more organic matter and more light energy can be converted into chemical energy.The heat dissipation ability of Rhododendron dauricum is stronger than that of Vaccinium uliginosum,which is weaker than that of Vaccinium vitis-idaea,The above results show that the blueberry has the strongest adaptability to the light environment of the growing land.