唐菖蒲光合特性的研究

采用光合作用测定仪和植物效率分析仪对生长在冀西北坝上高原唐菖蒲的光合特性和荧光参数生理生态特点进行了研究,结果表明:①夏季在晴天、土壤水肥充足条件下,唐菖蒲叶片的光合速率呈双峰曲线,其光饱和点为2145μmol/(m2.s),光补偿点为174.8μmol/(m2.s),净光合速率的最大值为36.4μmol/(m2.s),唐菖蒲为典型的阳性植物。②晴天唐菖蒲叶片的AQY由10:00时的0.0878下降到了13时的0.0640,PSⅡ最大光化学效率Fv/Fm由10时的0.79下降到14时的0.69,比最大值下降约13%,唐菖蒲在中午发生了一定的光抑制。③由叶片能量流动模型分析,高辐射使PSⅡ部分反应中心失活或降解,叶片遭受高辐射胁迫后启动了相应的防御机制,使过剩激发能得以及时耗散。由类囊体膜能量流动模型分析,高辐射导致叶片单位面积部分反应中心失活或裂解后,启动了剩余的有活性反应中心的补偿机制,使其能量传递效率提高。

Photosynthetic characteristics in leaves of Gladiolus

ZA field experiment was conducted in northwest plateau of Hebei province to study the photosynthetic characteristics and eco-physiological characteristics of chorophyll fluorescence parameters of gladioluswith ECA-PB0402 photosynthesis plant efficiency analyser.The results showed that: i) It was showed that the curve of net photosynthetic rate leaf determinator had two peaks on sunny day in summer under sufficient soil water and fertilizer conditions.The light compensation point was 174.8 μmol photons/(m2·s),the light saturation point 2 145 μmol photons/(m2·s),and the maximum net photosynthetic rate 36.4 μmolCO2/(m2·s),indicating that gladious is a typical light-favored plant. ii) In sunny day apparent quantum yield of gladiolus leaf decreased from 0.087 8 at 10 o′clock to 0.064 0 at 12 o′clock,the maximum PSⅡphotochemical efficiency(Fv/Fm) decreased from 0.69 by 13% compared with the maximum value,probably showing that photoinhibition was not very significant at noon.iii) In light of analysis of pipeline models for phenomenological fluxes(leaf model),deactivation or degradati on in part of reaction center was caused by high PAR and surplus excitation energy will dissipate in time,when leaf starts defense mechanism under high PAR.Through analysis of pipeline models for specific fluxes(membrane model),deactivation or degradation causes in part of reaction center of leaf unit area for high PAR,and leaf starts compensating mechanism in surplus fractions of reaction center to improve energy transfer efficiency.