盐胁迫对4种园林植物光合特性的影响

利用人工浇盐的方式模拟野外盐环境，测定了大红花、龙船花、鹅掌藤和朱蕉幼苗的光合指标，分析盐胁迫对4种植物幼苗叶片光合作用的影响。结果表明：随着盐胁迫时间的延长，在0.3%盐浓度情况下，4种幼苗的P_n呈下降的趋势；大红花的G_s不断下降，其他植物先降后升；大红花和鹅掌藤的C_i不断下降，龙船花先降后升，朱蕉持续上升；大红花的T_r不断下降，其他植物先降后升。在0.6%盐浓度情况下，4种幼苗的P_n不断下降；大红花、龙船花和鹅掌藤的G_s先降后升，朱蕉不断下降；大红花、龙船花以及鹅掌藤的C_i先降后升，朱蕉先升后降；4种幼苗的T_r先降后升。从4种植物的P_n、G_s、C_i和T_r综合判断，大红花和鹅掌藤抗盐胁迫能力强，龙船花的抗盐胁迫能力中等，朱蕉的抗盐胁迫能力最差。

Effects of NaCl Stress on Photosynthetic Characteristic of Garden Seedlings of 4 Species

The effects of NaCl stress on photosynthesis of seedlings of 4 species were studied to provide a reference for garden plant selection of salt tolerant. Seedlings of Hibiscus rosa-sinensis, Ixora chinensis, Schefflera arboricola, Cordyline fruticosa were placed in simulating salt environment, and then their photosynthetic indexes were determined. Results showed that at 0.3% salt concentration, with increasing salt stress time, Pn of the 4 species continuously decreased. Gs of H. rosa-sinensis continuously decreased, whereas the other species decreased followed by an increase. Ci of H. rosa-sinensis and S. arboricola continuously decreased, and I. chinensis decreased followed by an increase, C. fruticosa continuously increased. Tr of H. rosa-sinensi continuously decreased, and the other species decreased followed by an increase. At 0.6% salt concentration, Pn of seedlings of the 4 species continuously decreased. Gs of H. rosa-sinensis, I. chinensis and S. arboricola decreased followed by an increase, C. fruticosa continuously decreased. Ci of H. rosa-sinensis, I. chinensis and S. arboricola decreased followed by an increase, whereas C. fruticosa increased and then decreased. Tr of seedlings of the 4 species decreased followed by an increase. The overall judgment from Pn, Gs, Ci and Tr of the 4 plant species, H. rosa-sinensis and S. arboricola had stronger salt tolerance among 4 species and was more suitable for cultivation in salt land, and salt tolerance of I. chinensis was medium, whereas that of C. fruticosa was weaker.