Abstract
Avicennia marina seedlings were grown at 7 different levels of seawater (0, 25, 50, 75, 100, 125 and 150% seawater) in the greenhouse. The effect of external salinity on the early developmental stage of A. marina was studied by examining germination, the growth performance and photosynthetic rate. At lower salinity seed germination took place quickly and the germination percentage was higher than that in higher salinity. The optimal growth was recorded in 25% seawater. In the sodium chloride free medium the growth of seedling was inhibited. High salinity caused the increase of fallen leaves and decrease of the growth performance. However, all seedlings appeared to have grown up in higher external salinity. The photosynthesis was affected by external salinity, but A. marina could maintain the positive photosynthetic production at higher external salinity of 125 and 150% seawater. In conclusion, though salinity is an important factor which affects the establishment and growth of a seedling, A. marina appears to be an effective salt tolerant plant species.
