Abstract: One-year-old Aegiceras corniculatum seedlings were planted in pots under 3 light intensities, i.e., full sunlight, 45% sunlight, and 25% sunlight, aimed to study the eco-physiological responses of the seedlings to different shade levels after irrigated with fresh water and artificial seawater. After treated for 360 d, the annual increment of height growth at the same water salinities increased significantly with increasing light intensity, and had significant differences among the three light intensity treatments. On the contrary, the annual increment of stem diameter decreased significantly. The average branch number, leaf number, leaf area, and leaf thickness all existed significant differences among the treatments. At the same water salinities, the leaf chlorophyll a, chlorophyll b, and total chlorophyll contents had no significant differences under 25% and 45% sunlight but were significantly higher than those under full sunlight, while the chlorophyll a/b ratio had less difference among all the treatments. The net photosynthetic rate, soluble sugar content, nitrate reductase activity, and root vigor at same water salinities decreased significantly with the reduction of light intensity. Under the same light intensities, the seedlings irrigated with fresh water had lower soluble sugar content, nitrate reductase activity, and root vigor, compared with those irrigated with sea water. Our results indicated that shading had significant effects on the eco-physiology of pot-planted A. corniculatum.

Key words: Syringa L, Embryo, Culture in vitro