云南石林地区喀斯特山地种子休眠分类和生态关系的初步研究

种子休眠是植物自身调节后代繁殖时间节律以适应生长环境的最重要方式,喀斯特是一种特殊的植物生长环境,植物种子休眠对这种生境适应的研究缺乏.为探讨种子休眠与种子大小、散落时间之间的联系,揭示喀斯特植物在长期的适应过程中的生殖对策,对滇中喀斯特岩溶地区的19科35种植物的种子萌发和休眠类型进行了初步研究.结果表明:(1)35种植物中,休眠物种(19种,54.29％)比不休眠物种多(16种,45.71％)；(2)19种休眠的物种中,15种具生理休眠,4种具物理休眠,没有形态休眠、形态-生理休眠和联合休眠的植物；(3)具物理休眠的植物种子明显大于不休眠和生理休眠的植物种子；(4)雨季初期(4～7月)散落的种子不休眠比例很高(75.00％),而雨季后期(10月)和旱季(11月至次年3月)散落的种子的休眠比例很高,分别达80.00％和61.54％;(5)68.75％的乔木休眠；灌木的休眠比例为33.33％；藤本植物休眠和不休眠的物种比例相差不大；草本植物大部分(66.67％)不休眠.

Classification and ecological relationships of seed dor- mancy in Shilin of karst region, Yunnan Province

Seed dormancy is an important survival strategy adapted by plants to tune the time between seeds dispersal and right germination schedule.Seed germination characteristics and the class of seed dormancy(or non-dormancy) of 35 indigenous plants in limestone-forest region,Yunnan Province were examined.The results showed that the proportion of species with dormancy(D) seeds(19 species,54.29%) was higher than species with non-dormancy(ND) seeds(16 species,45.71%).Seeds of 15 species had physiological dormancy(PD),4 with physical dormancy(PY),and none of them had morphological dormancy(MD),morphophysiological dormancy(MPD) and combinational dormancy(PY+PD).Seeds of species with PY were significantly bigger than those species with ND and PD.The majority(75.00%) of species dispersed seeds in early rainy season(April-July) were ND type,however species dispersed seeds in late rainy season(October) and dry season(November-March) had high proportion of D seeds(80.00% and 61.45%).The majority of trees(68.75%) had dormant seeds,and the majority of shrub(66.67%) and grass(66.67%) had non-dormant seeds.