被子植物镜像花柱及其进化意义-JournalofSystematicsandEvolution.PDF

植 物 分 类 学 报 45 (6): 901–916 (2007) doi:10.1360/aps07042 Acta Phytotaxonomica Sinica 被子植物镜像花柱及其进化意义 林 玉 谭敦炎* (新疆农业大学林学院 乌鲁木齐 830052) Enantiostyly in angiosperms and its evolutionary significance * LIN Yu TAN Dun-Yan (College of Forestry Sciences, Xinjiang Agricultural University, Ürümqi 830052, China) Abstract Enantiostyly, deflection of style to left or to right side of floral axis, is a kind of style polymorphism. Based on organization of left- and right-styled flowers present on individual plants, enantiostyly can be expressed as two quite distinct forms: monomorphic and dimorphic enantiostyly. In monomorphic enantiostyly, individual plants produce both floral forms, either mixed within an inflorescence or segregated between left- and right-styled inflorescences, and this condition is not a genetic polymorphism. In dimorphic enantiostyly, plants are exclusively left- and right-styled, and this condition is a genetic polymorphism. Based on patterns of arrangement of style and stamens in individual flowers, enantiostyly can be expressed as reciprocal and nonreciprocal enantiostyly. Reciprocal enantiostyly is commonly associated with the reciprocal deflection of a pollinating anther, but in nonreciprocal enantiostyly there are no pollinating anther deflections. Enantiostyly has been reported in 11 families of angiosperm. It is generally considered to play an important role in (1) protecting the functional pistil and stamens, (2) insuring reproduction by selfing, and