Floral ontogeny of Knema and Horsfieldia (Myristicaceae): evidence for a complex androecial evolution
Floral ontogeny of Knema and Horsfieldia (Myristicaceae): evidence for a complex androecial evolution
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DOI：
10.1111/j.1095-8339.2010.01075.x
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发表时间：
2010-09
影响因子：
2.4
通讯作者：
Fengxia Xu;L. R. Craene
中科院分区：
文献类型：
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作者：
Fengxia Xu;L. R. Craene
使用扫描电子显微镜检查和描述了两种克尼玛和一种霍斯菲尔德花的花个体发育。花被三聚体，三个花被片连续生出。雌花有一个圆形的花尖，顶部凸出。单心皮原基沿着芽的边缘起始，并形成具有顶端双裂柱头的褶皱形状。在雄花中，花顶大致呈半球形，略呈三边形。几个花药原基几乎同时在花顶端边缘周围形成。在Horsfieldia中，雄蕊在花前群中横向延伸，而在Knema中，花药形成两个轮生。发现互生雄蕊与前雄蕊不同，后者被挤压在有限的空间内。花药原基与花托贴合并纵向生长，产生一对小孢子囊。花顶端的中心区域作为未分化的残留物持续存在，没有任何雌蕊的痕迹。肉豆蔻科花药基本上是同源的，尽管花药的数量、花粉囊和雄蕊的形状各不相同。雄蕊群的进化在该科中进行了讨论，肉豆蔻科中花药数量减少和增加的可能性相反。 © 2010 伦敦林奈学会，《林奈学会植物学杂志》，2010 年，164，42–52。
The floral ontogeny of two species of Knema and one of Horsfieldia was examined and described using scanning electron microscopy. The perianth is trimerous with three tepals arising in succession. Pistillate flowers have a rounded floral apex with a convex top. The single carpel primordium is initiated along the margin of the bud and develops a plicate shape with an apical bilobed stigma. In staminate flowers, the floral apex is broadly hemispherical with a somewhat three-sided shape. Several anther primordia are initiated almost simultaneously around the margin of the floral apex. In Horsfieldia, stamens extend laterally in antetepalous groups, whereas, in Knema, anthers form two whorls. The alternitepalous stamens were found to be different from the antetepalous stamens, which are pressed within a limited space. The anther primordia remain adnate to the receptacle and grow longitudinally, producing a pair of microsporangia. The central area of the floral apex persists as an undifferentiated residuum without any trace of a gynoecium. Myristicaceous anthers are basically homologous, although the number of anthers, pollen sacs and shape of the androecium are variable. The evolution of the androecium is discussed in the family, with opposing possibilities for reductions and increases in anther number in Myristicaceae. © 2010 The Linnean Society of London, Botanical Journal of the Linnean Society, 2010, 164, 42–52.