Intrafloral differentiation of stamens in heterantherous flowers  

作　　者：Zhong-Lai LUO Lei GU Dian-Xiang ZHANG 

机构地区：[1]South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China [2]Graduate University of Chinese Academy of Sciences, Beijing 100049, China

出　　处：《Journal of Systematics and Evolution》2009年第1期43-56,共14页植物分类学报（英文版）

基　　金：supported by National Natural Science Foundation of China (30570314);the Knowledge Innovation Program of Chinese Academy of Sciences (Grant No.KSCX2-YW-Z-027)

摘　　要：Flowers that have heteromorphic stamens （heterantherous flowers） have intrigued many researchers ever since the phenomenon was discovered in the 19th century. The morphological differentiation in androecia has been suggested as a reflection of ＂labor division＂ in pollination in which one type of stamens attracts pollinators and satisfies their demand for pollen as food and the other satisfies the plant＇s need for safe gamete dispersal. The extent and patterns of stamen differentiation differ notably among taxa with heterantherous flowers. Seven species with heteromorphic stamens in three genera were sampled from Leguminosae and Melastomataceae, and the morphological difference of androecia, pollen content, pollen histochemistry and viability, pollen micro- morphology, as well as the main pollinators were examined and compared. Pollen number differs significantly between stamen sets of the same flower in most species investigated, and a correlation of pollen number and anther size was substantiated. Higher pollen viabilities were found in the long （pollinating） stamens of Senna alata （L.） Roxb. and S. bicapsularis （L.） Roxb. Dimorphic pollen exine ornamentation is reported here for the first time in Fordiophytonfaberi Stapf. The height of stigma and anther tips of the long stamens in natural conditions was proved to be highly correlated, supporting the hypothesis that they contact similar areas of the pollinator＇s body.Flowers that have heteromorphic stamens （heterantherous flowers） have intrigued many researchers ever since the phenomenon was discovered in the 19th century. The morphological differentiation in androecia has been suggested as a reflection of ＂labor division＂ in pollination in which one type of stamens attracts pollinators and satisfies their demand for pollen as food and the other satisfies the plant＇s need for safe gamete dispersal. The extent and patterns of stamen differentiation differ notably among taxa with heterantherous flowers. Seven species with heteromorphic stamens in three genera were sampled from Leguminosae and Melastomataceae, and the morphological difference of androecia, pollen content, pollen histochemistry and viability, pollen micro- morphology, as well as the main pollinators were examined and compared. Pollen number differs significantly between stamen sets of the same flower in most species investigated, and a correlation of pollen number and anther size was substantiated. Higher pollen viabilities were found in the long （pollinating） stamens of Senna alata （L.） Roxb. and S. bicapsularis （L.） Roxb. Dimorphic pollen exine ornamentation is reported here for the first time in Fordiophytonfaberi Stapf. The height of stigma and anther tips of the long stamens in natural conditions was proved to be highly correlated, supporting the hypothesis that they contact similar areas of the pollinator＇s body.

关 键 词：buzz pollination heteranthery labor division pollen micro-morphology pollen number POLLINATION stamen differentiation. 

分 类 号：Q944.58[生物学—植物学]