海桑种子发芽条件的研究

Seed Germination Conditions of Sonneratia carseolaris of Mangrove

对影响海桑种子发芽的因子即光照、温度、海水盐度和pH值进行了研究．结果表明：海桑种子为需光种子，种子萌发需有光敏素的参与．缺乏光照是造成种子发芽率低和不整齐的主要原因，播种前将种子在湿润状态下用700lx的光照射24～36h或用体积分数为10－3的外源赤霉素（GA3）溶液浸泡36h，即可显著提高发芽率和发芽势；实验室发芽适宜温度为30～40℃，最适为35℃；海水盐度在10‰以下有利于海桑育苗，最适盐度为2．5‰；酸碱度对种子发芽影响不大，种子在pH为4～11时均可正常萌发生长．

The seed germination conditions, including illumination temperature, sea water salinity and pH value, of Sonneratia carseolaris have been studied systematically. The result indicates that S. carseolaris belongs to light-needed seeds, and the phytochrome is the necessary condition for the germination. The shortage of illumination is the major cause which makes the seeds having lower germinatiom percentage and the seedlings coming out unevenly.The seed germination percenage and energy could be increased remarkably when the seeds, before sowing, were illuminated with 700 lx lighting for 24～36 hours under moist condition or immersed in 1 000 × 10-6 gibberellin liquid for 36 hours. The temperature between 30～40℃ is suitable for the germination, 35 ℃ is the best in the laboratory. Lower than 10‰ sea water salinity are advantageous to raise seedlings, the best salinity is 2. 5‰ The acidity and alkalinity do not greatly affect the germination, for the seeds can germinate and grow normally in pH 4～11.