重庆喀斯特地区适生植物种子大小分布及吸水特征

Seed Size and Water Absorption Characteristics ofAdaptive Plants in a Typical Karst Region of Chongqing

对重庆典型喀斯特地区中梁山海石公园内21种适生植物成熟种子的形态、大小及吸水规律进行了研究.结果表明:1)该地区种子形态多趋近圆(球)形,部分种子有附属结构.2)种子的长度为1.278~14.946 mm,宽度为0.771~7.012 mm,长宽比为1.092~13.422;种子千粒质量分布为0~400 g,且集中分布在0~50 g区间内.3)种子吸水总体呈现先快后慢的特征,不同植物种子吸水率差别较大.可见,该地区适生植物种子多呈圆形或有附属结构以利于扩散,总体上采取小种子“r繁殖策略”及快速吸水等来适应干旱缺水、异质多样的喀斯特生境特征.

The study of the seed adaptability to karst habitat is very important for guiding the work of restoration of karst vegetation.An investigation was made about the seed morphology and size indexes,such as length,width and 1000-grain weight,of the mature seeds of 21 adaptive plants in Haishi Park,a typical karst area in Chongqing,China.The results showed that their seeds were generally small;seed morphology tended to be orbicular(spherical)in shape and some seeds had subsidiary structures.The length,width and length/width ratio of the seeds varied in the ranges of 1.278-14.946 mm,0.771-7.012 mm,and 1.092-13.422,respectively.Their 1000-grain weight ranged from 0 to 400 g,mostly in the range of 0-50 g.Seed water absorption generally showed a trend of“a rapid rise first followed by a slow drop”.There were significant differences in seed water absorption rate among different plants.Therefore,the seeds of adaptive plants in this karst region were mostly round or had subsidiary structures to facilitate their diffusion.Generally,these plants adopted the“r”strategy and rapid water absorption to adapt to the dry and heterogenous habitat in karst areas.