【摘要】 利用扫描电镜首次观察了天南星科花叶芋(Colocasia bicolor) 的花器官发生过程。花叶芋的肉穗花序由无花被的单性花构成, 雌花发生于花序基部, 雄花发生于花序上部, 中性花位于花序中间部位。雄花: 3 或4 个初生雄蕊原基轮状发生, 随后每个初生原基一分为二, 形成6或8个次生原基; 一部分次生原基在其后的发育过程中融合, 形成5 或7 枚雄蕊; 雄花发育过程中未见雌性结构的分化; 花药的分化先于花丝; 雄蕊合生成雄蕊柱。雌花: 合生心皮, 3或4个心皮原基轮状发生, 未见雄性结构的分化。中性花来源于雌雄花序过渡带上, 属于雄蕊原基的滞后发育以及发育成熟过程中的退化; 与彩叶芋属(Caladium)不同, 此过渡区未见畸形两性花。初生雄蕊原基二裂产生次生原基的次生现象在目前天南星科花器官发生中显得比较特殊, 同时初步探讨了次生原基的融合方式。更多还原

【Abstract】 In the present study,the floral organogenesis of Colocasia bicolor,a newly-described species from China,belongs to the family Araceae,has been observed for the first time under the scanning electron microscope (SEM).The spadix of C.bicolor contains unisexual flowers without a perianth.The pistillate flowers are initiated on the basal portion of the inflorescence,and the staminate flowers are initiated on the apical portion.There is a narrow zone between the male flowers and female flowers consisting of neutral flowers.In the staminate flowers,three or four primary stamen primordia arise in a whorl,then,each of them splits into two secondary primordial.Some secondary primordia of a male flower fuse and form five or seven stamens,but no female structures are formed.Anthers are differentiated prior to the filaments formation.Six to eight (sometimes five) stamens are connate into a synandrium.In the female flowers,three or four carpel primordia arise in a whorl.In contrast,no male structures are formed.Neutral flowers derived from the delayed development and the degeneration of stamen primordia in the course of development.The spadix of Colocasia is different from those of Caladium,by lacking atypical bisexual flowers between the female and the male zone.The staminate primary primordia with ability of splitting up into two secondary primordia indicate some particular in Araceae.In addition,the fusion style of secondary primordia on C.bicolor is mentioned.更多还原