胎生红树植物繁殖体特征与繁殖扩散的关系研究

Study on the Relationship between Propagule Characteristics and Reproductive Dispersal of Viviparous Mangrove Plants

为了探索红树林胎生红树植物繁殖体特征与繁殖扩散的关系,分析对比我国3种最常见胎生红树植物白骨壤(Avicennia marina)、桐花树(Aegiceras corniculatum)和木榄(Bruguiera gymnorhiza)的繁殖体质量、长度、体积和密度,并利用室内漂浮和繁殖体萌发实验探究其在不同盐度条件下的漂浮性和萌发状态。结果发现,3种红树植物的繁殖体密度均略小于1.000 g/cm^(3);在不同盐度条件下,白骨壤繁殖体的漂浮性存在显著差异,萌发率高且萌发时间远早于木榄;而桐花树繁殖体具有下沉性且漂浮性差,部分桐花树繁殖体仅在实验结束后才长出根系;木榄繁殖体则表现出极好的漂浮性(漂浮率均>85%),低盐条件下萌发率高。以上说明,白骨壤繁殖体的极强适应性、木榄繁殖体的强漂浮性等为其成为广布种提供了基础支撑。胎生红树植物的繁殖体自身形态、漂浮性、萌发状态等特征,对其繁殖定植有很大影响。本研究有助于解释红树植物的繁殖扩散,对于红树林的保护和恢复有较重要的意义。

To explore the relationship between propagule characteristics and reproductive dispersal of viviparous mangrove plants,the mass,length,volume and density of propagules of three most common viviparous mangrove plants in China,Avicennia marina,Aegiceras corniculatum and Bruguiera gymnorhiza,were analyzed and compared,and their floating and germination status under different salinity conditions were explored by indoor floating and propagule germination experiments.The results showed that the propagule density of the three mangrove species was slightly less than 1.000 g/cm^(3).Under different salinity conditions,the floating ability of Avicennia marina propagules was significantly different,the germination rate was high and the germination time was much earlier than that of B.gymnorrhiza.However,the propagules of Aegiceras corniculatum had sinking and poor floating ability,and some propagules of Aegiceras corniculatum only grew roots after the experiment ended.B.gymnorhiza propagules,on the other hand,exhibited excellent floating ability(floating rate>85%)and had a higher germination rate under low salinity conditions.The above shows that the strong adaptability of Avicennia marina propagules and the strong floating ability of B.gymnorrhiza propagules provide a foundational support for its widespread distribution.The characteristics of the propagules of viviparous mangrove plants,such as their own morphology,floating ability and germination status,have a great effect on their reproduction and establishment.This study helps to explain the reproductive dispersal of mangrove plants,which is of great significance for the protection and restoration of mangrove forests.