太湖常见浮叶植物和沉水植物的光合荧光特性比较

利用水下饱和脉冲荧光仪(DIVING-PAM)，原位观测太湖常见的水生植物菱、荇菜、苦草、黑藻的最大光化学量子产量(F_v/F_m)及在暗适应和光适应条件下的快速光曲线.结果表明:浮叶植物菱和荇菜光系统Ⅱ的潜在最大光合作用能力高于沉水植物苦草和黑藻,其最大量子产量分别为0.837、0.831、0.684和0.764;菱和荇菜的最大电子传递速率、半饱和光强分别高于沉水植物苦草和黑藻,且在光适应条件下尤为显著.

Photosynthetic fluorescence characteristics of floating-leaved and submersed macrophytes commonly found in Taihu Lake.

Some aquatic macrophytes commonly found in Taihu Lake, including Trapa bispinosa, Nymphyoides peltatum, Vallisneria natans, and Hydrilla verticillata were collected, and their maximal quantum yield of photosystemⅡ(Fv/Fm) as well as the rapid light curves (RLCs) under conditions of light adaptation and dark adaptation were measured in situ by using a submersible and pulse-amplitude modulated fluorometer (Diving-PAM). The results showed that floating-leaved plants T. bispinosa and N. peltatum had higher potential maximum photosynthetic capacity than submerged macrophytes V. natans and H. verticillata. The measured maximal quantum yield of T. bispinosa, N. peltatum, V. natans, and H. verticillata was 0837, 0831, 0684, and 0764, respectively. Both the maximal relative electron transport rate and the half saturation point of light intensity of T. bispinosa and N. peltatum were higher than those of V. natans and H. verticillata, especially under the condition of light adaptation.