[Effects of silicon on exchange characteristics of H2O and CO2 in ginger leaves]

With solution culture, this paper studied the effects of silicon (Si) on the plant growth, Si content, photosynthetic rate, and transpiration rate of ginger (Zingiber officinale Rosc. ) cultivar, Laiwu big ginger. The results indicated that the biomass per plant and the leaf Si content were increased dramatically with increasing Si level in culture solution. In treatments T1 (1.0 mmol Si x L(-1)), T2 (1.5 mmol Si x L(-1)), and T3 (2.0 mmol Si x L(-1), the leaf Si content was increased 604.4%, 834.8%, and 1130.4%, and the biomass per plant was increased by 9.4%, 19.4%, and 22.8%, respectively, compared with the control. With increasing Si level, the leaf Mg2+ -AT-Pase and Ca2+ -ATPase activities, photosynthetic rate (Pn), and water use efficiency (WUE) increased, while the transpiration rate (Tr) decreased. At 11:00 o'clock, the Pn in treatments T1, T2, and T3 increased by 11.2%, 21.8%, and 28.2%, WUE increased by 23.1%, 55.9% and 54.8%, while Tr, decreased by 6.3%, 17.1% and 19.2%, respectively, compared with the control. Si also improved the leaf light saturation point (LSP), carboxylation efficiency (CE), and carotenoid content significantly, but had less effect on chlorophyll content. In our study, the suitable Si concentration for ginger was 1.5-2.0 mmol x L(-1).