摘要
野外调查了青藏高原特有植物肋果沙棘的花期物候、开花式样以及风媒传粉特征,对其花粉生活力、柱头可授性及单花花粉量进行了检测。结果表明,肋果沙棘有许多适应风媒传粉的特征：雌雄异株,花小,无花冠,先叶开放,雄花萼片纵裂形成对流的＂风洞＂,花粉近球形,单花花粉量大;雌花柱头细长捻状,伸出萼筒,授粉面大,密布乳突。花粉生活力可以持续16.5 d,柱头可授性为10-20d。肋果沙棘传粉多发生在昼夜温差大的5月中下旬,在多变的气候条件下,种群花期可持续约12-25d,但在晴朗的天气条件下具有爆发性的集中开花机制,是对恶劣条件的适应。重力玻片法检测表明,离花粉源15m左右远的地点花粉密度最大,135m仍能接收到花粉,夜间接收到的花粉数量也很可观,这些研究结果表明,该植物集中在有利的晴朗天气昼夜进行长距离的风媒散粉,能较好地适应青藏高原的复杂环境。
The flowering phenology,floral design and characteristics of wind pollination in Hippophae neurocarpa S.W.Liu et T.N.He endemic to the Qinghai-Tibet plateau were investigated in field.We examined pollen viability,stigmatic receptivity and pollen production in this species respectively.The results showed that the shrub adapted to anemophily with dioecism,small flowers,no corollas,flowering before leaf emergence,the sepals of staminate flowers vertical spited and formed a wind-tunnel through which pollen dispersed.Male flowers produced a large number of subsphaeroidal pollen grains,while female flowers had one slender and twisted stigma protruding calyx tube and a relatively large surface area covered with mastoids densely.The pollen viability and stigmatic receptivity could last 16.5 d and 10 to 20 d respectively.Pollination of this shrub often occurred in mid-and late of May.Population flowering phase last about 1225d in variable weather,but pollen is explosively released in fine days to reduce pollen loss in unfavorable environments.The results of gravity slide indicated the highest pollen density appeared at about 15m away of the pollen source and the pollen could reach 135m.We found the amount of pollen on slides during the night was also considerable high in fine days.These findings indicated that explosive pollen dispersal by wind in Hippophae neurocarpa in favorable weather was an adaptive strategy in the Qinghai-Tibet Plateau of China.
出处
《生态学报》
CAS
CSCD
北大核心
2009年第1期508-514,共7页
Acta Ecologica Sinica
基金
国家自然科学基金资助项目(30570110)
关键词
肋果沙棘
自然种群
风媒传粉
Hippophae neurocarpa S.W.Liu et T.N.He
natural population
wind pollination
