中文摘要：

用PAM2000型便携式荧光测定系统测定了不同浓度Narciclasine（NCS）处理的离体萝卜子叶的荧光动力学参数：初始荧光（F0）、光化学淬灭（qP）、光系统Ⅱ最大光化学效率（Fv／Fm）、光合电子传递速率（ETR）。结果表明，NCS对各种叶绿素荧光参数均显示出明显的抑制作用，而且NCS的抑制作用随其浓度的增加而逐渐增强；利用蓝绿温和胶电泳技术分析萝卜子叶类蠼体膜蛋白复合物发现，转绿期间叶绿体中光系统Ⅱ（PSⅡ）和光系统捕光色素蛋白复合体的含量增加均被NCS抑制。表明从水仙鳞茎分泌物中分离提取的生物活性物质NCS能够明显抑制离体萝卜子叶的光下转绿。而且NCS对离体萝卜子叶光下转绿的抑制是多位点的。

英文摘要：

PAM2000 Chlorophyll Fluorometer was employed to the parameters of in vitro cotyledons in fluorescence kinetics at different narciclasine concentrations,initial fluorescence （Fo） ,photochemical quenching coefficient （qP）, maximum photochemical efficiency of PS Ⅱ （Fv/Fm） and photosynthetic electron transport rate （ETR）. The results showed that narciclasine presented inhibitory effects on various chlorophyll fluorescence parameters which became intensified as narciclasine concentration increased ; it was shown in the analysis of thylaoid-membrane protein complexes in the cotyledons of radish by Blue-native polyacrylamide gel electrophoresis to inhibit the increasing of PS Ⅱ and light-harvesting chromoprotein complex in the chloroplasts during cotyledon virescence. These indicated that narciclasine,a bioactive subtance isolated from the secretion of Narcissus tazetta L. bulbs,could remarkably inhibit the virescence of in vitro cotyledons of radish under light and its inhgibitory effect involved multiple sites.