小慈姑的开花状态、传粉机制与交配系统  

FLORAL EXPRESSION, POLLINATION MECHANISM AND MATING SYSTEM OF SAGITTARIA POTAMOGETIFOLIA

作　　者：汪小凡[1] 陈家宽[2] 

机构地区：[1]武汉大学植物发育生物学教育部重点实验室,武汉430072 [2]复旦大学生物多样性与生态工程教育部重点实验室,上海200433

出　　处：《植物生态学报》2001年第2期155-160,共6页Chinese Journal of Plant Ecology

基　　金：国家自然科学基金资助项目! (39870 0 82 )

摘　　要：在自然种群中对沼生植物小慈姑 (Sagittaria potamogetifolia Merr.)的开花状态和传粉过程作了观测 ,并用同工酶遗传标记法定量估测了其 3个种群中 5个样本的异交率。该种为虫媒传粉为主的虫媒 /风媒兼性传粉机制 ,访花昆虫的飞行距离多在 0～ 2 m范围内 ,并与花序密度呈不显著的正相关。异交率 (t)为 5 0 .0 %～ 92 .8% ,表明该种为异交为主的混合交配系统 (Mixed m ating system)。对雌雄同株的小慈姑而言 ,异交率与各种群花期植株密度无关 。The floral expression and pollination mechanisms of Sagittaria potamogetifolia Merr., a helophyte species, were observed in natural populations. The species is insect and, concurrently, wind pollinated, but pollen flows are mediated mainly by insect pollination. The movements of pollinators are correlated with densities of inflorescence in populations, because the insect visitors have a certain capability to adapt to variations in population density. Outcrossing rates of 5 samples from 3 populations were quantitatively estimated by sampling from natural habitats and using an isozyme locus as a genetic marker. The outcrossing rates in the 5 samples (50 0%-92 8% ) indicate a mixed mating system dominated by outcrossing mechanisms. For the monoecious species S. potamogetifolia Merr., outcrossing rates are not correlated with densities of blooming plants in populations, but the level of outcrossing is dependent on the frequencies of individuals bearing more than two inflorescences.

关 键 词：小慈姑 开花状态 传粉机制 交配系统 异交率 

分 类 号：Q346[生物学—遗传学]