掌状冠盖藻有性生殖过程中的光效应和光受体

以采自厦门海滨的中心硅藻掌状冠盖藻为实验材料，研究光对其有性生殖的影响。结果表明：诱导该藻有性生殖发生的临界日长为12h，其性化强度随光期加长与光强加大而增强，红光比白光的性分化诱导能力强，蓝光无诱导效应，设置光强度低于光合补偿点的白光或红光的加长光期，无论置于主光期之前或之后均能启动该藻性化反应，蓝光无效。从而获知，该藻至现长日照植物特征，光周期反应特性类似于光控类型，但却不具有夜中断反应，有性生殖过程中可能受红光受体的调控。

Light Effect and Photo-Receptor in the Sexual Reproduction Process of Stephanopyxis palmeriana

Centric diatom Stephanopyxis palmeriana was collected from seacoast of Xiamen and was cultured in laboratory. The influence of light to the sexual reproduction was studied. The results showed that a day length longer than a critical day-length of 12 h could evoke the sexual reproduction of S. palmeriana(Fig.1,Table 1). The sexualization rate increased with the prolongation of light period as well as with the enhancement of light intensity(Fig.2). Red light was more efficient in inducing sexual reproduction than white light, while blue light was ineffective(Table 2). Experiments on the effect of extending of day length showed that either red or white light could induce sexualization when added either before or after the main photoperiod. Blue light was ineffective when used as extension light in the experiment(Table 3). The results suggest that S. palmeriana is a long-day plant. Its photoperiodic response is similar to light-dominated reaction and the light signals were received by red-light receptor which mediates the photoperiodic response.