蜀葵花蜜成分与虫媒传粉模式的研究

Nectar Compositions and Insect Pollination of Althaea rosea

蜀葵(Althaea rosea)是我国一种重要的传统花卉,其花具有雌雄异熟和雌雄异位两种特征,柱头能发生弯曲与自身花粉接触,存在潜在的延迟自交。为了检测蜀葵花蜜成分和观察访花昆虫的访花行为,在自然居群内观察蜀葵花期物候、访花昆虫种类及主要访花昆虫的访花行为,采用高效液相色谱法分析其花蜜的主要成分和含量。结果表明,蜀葵每株每天开放0～40朵花,平均具有23朵处于不同发育时期的花。蜀葵的花朵在开花前分泌花蜜,单花花期内花蜜分泌呈单峰曲线。花蜜含糖量为8.41%,共检测出14种氨基酸。访花昆虫13种,主要为意大利蜂(Apis mellifera),其访花频率与花开放时间和花蜜分泌的高峰时间一致。意大利蜂在同一植株上访花数超过1朵的访问比例约占66.04%。蜀葵内同株异花传粉导致的双亲近交不可避免,两性花中的雌雄异熟和雌雄异位的适应意义可能主要是避免雌雄干扰。

Hollyhock（Althaea rosea） is an important traditional flower of china.A combination of dichogamy and herkogamy in the flower,meanwhile,the stigmas can curve and contact its own pollen,indicating the potential of delayed selfing.In order to detect the composition of nectar and observe the behavior of visiting,the flowering phenology,the species and visiting behavior of flower-visiting insects on Althaea rosea were investigated in naturalized population.The nectar content was determined by high performance liquid chromatography and analyse the compositions.Each individual plant has an average of 23 flowers in different developmental stages ranging from 0 to 40.The nectar is secreted before flower opening and has a single-peak curve in anthesis.The content of sugar is 8.41% in nectars,and 14 amino acids are detected in them.There are 13 flowering-visiting species and Apis mellifera is the main pollinator,the visiting frequency of Apis mellifera is correlated with the time of flower opening and the peak of nectar secreting.Among the pollinators＇,the proportion of geitonogamous visits within an individual plant occupied 66.04%.Biparental inbreeding is unavoidable in this species,the evolutionary mechanism of dichogamy and herkogamy in hermaphrodictic plants is to reduce intrafloral male-female interference