生姜光合效率日变化的研究

生姜生长期间，午间强光使叶片光合速率（Pn)、表观量子效率（AQY）及PSⅡ的光化学效率（Fv/Fm)下降，即表现为光抑制。苗期因光照强、温度高、AQY，Fv/Fm较低，光换制较重；随季节进展及光、温等条件的改善，光抑制减轻。对生姜遮荫可提高AQY和Fv/Fm，降低光抑制，但由于遮荫降低了羧化效率（CE），使Pn明显下降。据此，对有关遮荫理论及AQY等指标的应用进行了讨论，并提出改革当前遮荫方式的设想。

Studies on the Diurnal Changes of Photosynthetic Efficiency of Ginger

During ginger growth,the photoinhibition of photosynthesis and the diurnal variation of photosynthetic efficiency of ginger( Zingiber officinale Rosc.)were measured with LI 6200 portable photosynthesis system and PEAMK II plant efficiency analyzer under shade and field conditions.The results showed that there were markedly photoinhibition phenomena under high light stress at midday.The apparent quantum yield(AQY)and photochemical efficiency of PSII(Fv/Fm)decreased at midday,and they had a marked diurnal variation.The extent of photoinhibition was serious in seedling stage because of higher light intensity,then the extent of photoinhibition reduced as growth phase progressed and PFD decreased.After shading,AQY and Fv/Fm increased,the degree of photoinbition declined markedly.The more shading,the less the extent of photoinhibition was,but photosynthetic rate(Pn)would declined because carboxylation efficiency(CE)declined after shading.It was proposed to reform the present shading way in this papper.