Studies On Daily Patterns Of Photosynthesis For Polygonetum Odoratum

Diurnal change characteristic of photosynthesis and stomatal movement of polygonatwn odoratum were studied in this experiment The photosynthesis characteristics were measured by CI-301PS photosynthesis measure system. Stomatal characteristics was studied by electronic microscope. The results were indicated that the diurnal curve of net photosynthetic rate for polygonatwn adoration was a single-peaked pattern in whild condition, and net photosynthetic rate in June, July and August were higher than the other Months. Shading and fixed temperature can not affect diurnal curve pattern of net photosynthetic rate for polygonatwn odoratum. CO₂ compensation point changes as a single-peaked and apparent quantum yield changes on the opposite direction, but quanta apparent quantum yield keep eternally under fixed temperature. Different water condition of soil and plant make no effect on diurnal pattern of net photosynthetic rate and stomata resistance of polygonatwn odoratum, but can change it's leaf water potential. High CO₂ concentration can promote photosynthesis, make it keep a high net photosynthetic rate in the afternoon. Small amount of photosynthesis production can promote the improve of net photosynthetic rate, but large quantity of photosynthesis production of can prevent it's improvement, however the photosynthesis production can not change the form of diurnal pattern of net photosynthetic rate. Stomatal aperture of polygonatwn adoration was non-uniform closure in the day, most of the stomatal's aperture between 0.2-0.5 Stomatal aperture was greatly related to net photosynthetic rate, transpiration rate and stomatal conductance. The intercellular CO2 concentration was not the same under different stomatal, and they are related greatly by a logarithm equation.