香蕉叶片Chlα荧光动力学参量对激发光强的反应

RESPONSES OF THE CHLOROPHYLL FLUORESCENCE DYNAMIC PARAMETERS TO EXCITED LIGHT INTENSITY IN LEAF OF BANANA

在蓝色激发光(λm＝660nm)作用下，香蕉叶片的叶绿素a(Chl a)发出波长为720～740nm的荧光信号，荧光强度随时间呈现有规律的变化。随着激发光强的增加，荧光动力学参量F０和FVI／ＦＶ呈上升趋势，FＶ／Ｆ０与FＶ／ＦＭ逐渐达到饱和，而CA和T１／２呈下降趋势。研究结果表明，保证香蕉叶片光合机构高速有序运转的适宜光强在20～６０mol·m－２·s－１之间，过量的光强将造成叶片光合机构的损伤。讨论了香蕉叶片诸荧光动力学参量的生物学意义及其随激发光强度增加而变化的原因.

Under the irradiation of blue excited light ( λm＝660nm),the chlorophyll in leaf of banana gave a signal of fluores cence which the wavelength ranged from 720nm to 740nm.The intensity of fluoresce nce changed with the irradiation time regularly.When the intensity of excited li ght increased, thevaluesofchlorophyllfluorescencedynamicparametersF０andFＶ１／ＦＶincreased too,FＶ／Ｆ０andFＶ／ＦM were gradually saturated,CA and T１／２ de creased.The results of study showed that the light intensity of 20～60μE·m －２·s－１ was ensured for photosynthesis system.The biological signifi cance of chlorophyll fluorescence dynamic parameters and the reasons for change of the parameters to the increases of excited light intensity were discussed.