【摘要】 绿豆叶圆片用0、-0.3、-0.6、-1.2、-1.8、-2.4MPa等6个渗透梯度处理24h后,其叶绿素荧光的反应表明:光系统 的潜在量子产量 Fv/Fm 和电子传递受体 QA 的库容 poolsize 均随胁迫强度的增大而减小,但QA库容的下降明显比Fv/Fm的下降缓和.结合原初荧光Fo和最大荧光Fm的变化,分析认为本实验中渗透胁迫并未导致明显的光系统 反应中心的失活或破坏.造成光系统 潜在量子效率降低的原因主要是通过光系统 反应中心到QA的电子传递受到阻抑.更多还原

【Abstract】 Leaf discs of mungbean (Phaseolus aureus Roxb.) were submitted to six osmotic treatments,i.e.,0,-0.3,-0.6,-1.2,-1.8,-2.4 MPa,for 24 hours.After dark adaptation,randomlyselected 10 leaf discs were measured using a portable fluorometer (Handy PEA,Hansatech Instruments Ltd.,UK) in the dark room.Results showed that the potential quantum yield of PSⅡ and the pool size of PSⅡ electron transport accepters (QA) were both reduced by treatments of osmotic stress.The mild osmotic treatments of -0.3 and -0.6 MPa had smaller,while moderate and severe treatments had larger influence.Associated with the Fo and Fm values in all treatments,it was suggested that osmotic stress had slight effects on the pool size of QA and did not induce the apparent inactivation or damage to PSⅡ reaction centers.The main reason for the reduced potential quantum yield of PSⅡ (Fv/Fm) was the blocking of electron transport from PSⅡ reaction center to QA.更多还原