花冠闭合现象对高山植物喉毛花繁殖适合度的影响

Effects of floral closure on reproductive fitness of Comastoma pulmonarium

【目的】探究高山植物中花冠闭合现象的诱导机制及其对繁殖适合度的影响.【方法】以龙胆科喉毛花(Comastoma pulmonarium)为研究对象,测量花冠开放和闭合过程中环境温度的变化,观测人工授粉对花冠开合状态的影响,并比较人为制止两种花冠闭合现象后其雌雄繁殖适合度的变化情况.【结果】喉毛花的暂时性花冠闭合现象受低温诱导,制止暂时性花冠闭合后,剩余花粉数量显著减少,受精率降低,种子数量显著减少;授粉因素诱导喉毛花发生永久性花冠闭合现象,制止永久性花冠闭合后,种子的百粒质量和萌发率均显著降低.【结论】两种类型的花冠闭合现象共同提高了喉毛花的雌雄繁殖适合度及其对高山环境的适应能力,是喉毛花对高山胁迫生境长期适应的结果.

【Objective】In order to explore the mechanisms of floral closure phenomena in alpine plants and their effects on reproductive fitness.【Method】In this paper,Comastoma pulmonarium(Gentianaceae)was taken to explore the effects of ambient temperature and artificial pollination on floral closure.Besides,changes in reproductive fitness were compared after two types of floral closure phenomena were artificially restrained.【Result】The temporary floral closure of C.pulmonarium was induced by low temperature.When restraining it,the number of remaining pollen declined significantly,and the number of seeds was significantly reduced due to the decrease of fertilization ratio.Permanent floral closure was induced by pollination.The 100-seed weight and seed germination rate decreased significantly when the permanent floral closure was restrained.【Conclusion】Two types of floral closure phenomena of C.pulmonarium were the result of long-term adaptation to alpine habitats,which improve its reproductive fitness and adaptability to alpine environments.