作 者 ：孟雅冰
期 刊 ：西北植物学报 2015年 2期 页码：1685~1692
Keywords:Marrubium vulgare, synaptospermy, appendage, spread, intermittent germination,
摘 要 ：欧夏至草（Marrubium vulgare）为唇形科多年生植物，其扩散单元主要由集合繁殖体和种子组成，本文以单萼筒集合繁殖体为研究材料，比较其和种子在形态特征、扩散行为及萌发特性上的差异，探讨附属物的生态功能及对可变环境的适应对策。结果如下：（1）集合繁殖体是具萼筒的种子，其质量远大于种子；附属物能保护种子免受机械损伤或逃避捕食者。（2）在自然生境中，集合繁殖体易借风力扩散到较大范围，室内扩散实验表明，静止空气中集合繁殖体比种子降落所需的时间更长、扩散能力更强；集合繁殖体是种子延迟扩散的一种适应策略，其附属物的存在与否直接导致了种子扩散能力与扩散距离的差异，支持“Alternate假说”。（3）集合繁殖体和种子在活力、萌发率及萌发速率方面均不存在显著差异（P>0.05），而吸水率远大于种子，附属物的存在是影响种子承载更多水分并更长期保留水分的重要原因；集合繁殖体内种子的萌发属随机萌发，不具有位置效应，在当季只萌发部分种子，符合间歇性萌发特性，能有效避免种群覆灭。研究结果表明，多年生植物其扩散单元的形态特征和萌发行为对于种群的生存重要性相对低，母株可以长期占据原有生境，保持种群个体数量，附属物的作用主要用于种群扩散。
Abstract:Marrubium vulgare (Labiatae) is a perennial plant which its dispersal unit is composed of synaptospermy and seed. Our aim was to determine the morphological，dispersal behavior and germination characteristics of synaptospermy and seed, also discuss the ecological significance of appendage and the adaptive strategy of varied environment. Main results are as follows: (1) Synaptospermy means seeds in appendage, which mass is larger than seed; the function of addpendage is not only can protect seed from the mechanical damage but also stay away form predators. (2) In natural habitat, synaptospermy could spread to a long distance easily by the wind, indoor experiments indicate that synaptospemry spent more time than seed to landing, and had more ability of spreading; synaptospermy is a kind of adaptive strategy of dalayed spread, the appendage is the key of the difference of the spread ability and distance, which support “Alternate” hypothesis. (3) There are no differences in vigor, germination percentage and germination rate (P>0.05) of synaptospermy and seed, but the water absorption rate of synaptospermy was higher than seed, this shows that the appendage can affect seed to carry more water and retain it longer; the germination of synaptospermy belongs to random germination, which do not have position effect, only part of the seeds germinated in one season, which accord with the intermittent germination characteristic, this characteristic can avoid the risk of destruction of population effectively. These results suggest that the morphological characteristic and the germination behavior of the dispersal unit are lower of perennial, which relatived to the importance of the survival of the population. The mother plant of perennial can occupy original habitat for a long-term, keep the number of the individual of population, and the main function of appendage is spreading.