关键词: 保水剂, 烟草, 光合特性, 叶绿素荧光参数

Abstract: This paper studied the effects of different dosage of water retaining agent on growth parameters, chlorophyll content, photosynthetic characteristics and chlorophyll fluorescence parameters in tobacco by pot experiments. The results showed that: the application of appropriate amount of water retaining agent could significantly increase the contents of growth index, chlorophyll a, chlorophyll b and total chlorophyll in tobacco. The net photosynthetic rate (Pn), transpiration rate (Tr), stomatal conductance (Gs) and water use efficiency (WUE) of the treated tobacco increased firstly and then decreased with the application quantity growing of water retention agent. Results showed that the effect of water retaining agent on tobacco photosynthetic characteristics  was obvious, it could improve tobacco photosynthetic capacity, but over usage would be unvaverable for improving   tobacco photosynthetic characteristics. The treated tobacco chlorophyll fluorescence parameters Fv/Fm, ΦPSII and qP increased firstly and then decreased slightly, while the NPQ showed a down trend. Of all treatments, the effect of T2 (3 g/strain) was the best, its photosynthetic capacity was the strongest, and the treated tobacco had better ability of self protection and adjustment.

Key words: water retaining agent, tobacco, photosynthetic characteristics, chlorophyll fluorescence parameters