孑遗植物银杏(Ginkgo biloba L.)伴性光合生理特征与进化生态

银杏类是一类古老的雌雄异株植物,目前仅存单科单属.由于银杏在系统发育等方面的独特地位,吸引了科学家从不同方面进行了广泛的研究.在适宜的条件下,测定了生长在野外环境下的成年银杏的雌雄个体的光合特性.研究结果表明,银杏的雌雄植株对光具有相同的表现趋势,光饱和点,光补偿点,光下呼吸速率等均没有明显差异.但是雌性银杏的净光合速率明显大于雄性银杏的净光合速率.这种差异可能与雌性个体在繁衍后代时需要投入更多的能量有关.研究也表明,在与其它的裸子植物和被子植物比较时,银杏的光合能力并没有明显的弱势,因此光合能力可能并不是银杏在第三纪分布受限的直接原因.

Sex-linked photosynthetic physiologic research and the evolutionary ecological analysis in living fossil plant, Ginkgo biloba L.

Ginkgo is an ancient dioecious plant. At present, only Ginkgo biloba L. still exists as a living fossil plant. Botanists have studied it from different aspects in the world due to its unique characteristics. Plant sex physiological ecology is still a knowledge gap in plant ecology. This article measured the photosynthetic traits of adult male and female ginkgoes which grew in suitable environment condition. The result indicated that male and female ginkgoes had similar response to light. The light saturate points (LSP), light compensate point (LCP) and dark respiration rate (Rd) between male and female were also of insignificant differences. However, the net photosynthetic rate (Pn) of female ginkgo was significantly higher than male. From the view of evolution and through comparison with other gymnosperms and angiosperms, the photosynthetic capacity of ginkgo is not obviously lower than that of other plants. It gave us a clue that the photosynthetic capacity was not the direct reason, which restricted the distribution of ginkgo in the Tertiary.