Floral organogenesis of Helleborus thibetanus and Nigella damascena (Ranunculaceae) and its systematic significance
Floral organogenesis of Helleborus thibetanus and Nigella damascena (Ranunculaceae) and its systematic significance
复制标题
铁嚏根和大马士革黑种草（毛茛科）的花器官发生及其系统意义
DOI：
10.1111/j.1095-8339.2011.01142.x
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发表时间：
2011-08-01
影响因子：
2.4
通讯作者：
Ren, Yi
中科院分区：
文献类型：
--
作者：
Zhao, Liang;Liu, Ping;Ren, Yi
利用扫描电子显微镜和光学显微镜对黑麦草和黑麦草的花器官发生进行了观察和比较，并分析了黑麦草和黑麦草之间的关系。花瓣、花瓣、雄蕊和心皮的发育具有共同的特征，这些特征也存在于毛茅科的其他成员中。然而，它们在心皮的数目和合生程度上有很大的不同：在海贝塔中，两个心皮在底部稍微结合，而在大马士革中，雌蕊是合心的，五个心皮在整个子房中结合在一起。在花瓣发育方面也存在差异。黑斑潜蝇幼花瓣的叶片发育成两个凸起，这两个凸起合生，然后与侧面的叶片融合，比叶片发育得更快，形成管状花瓣。在大马士革夜蛾中，花瓣叶片上形成单一的脊状突起，发育成双唇形花瓣较小的近轴唇瓣，而叶片本身发育成较大的背轴唇瓣，具有两个假突起。在Helleborus中，最外层的雄蕊发育延迟，但在Nigella中没有。虽然我们的调查结果是初步的，但花发育特征的差异表明Helleborus和Nigella可能没有密切的亲缘关系，可能支持将它们归入不同的部落。
Floral organogenesis in Helleborus thibetanus and Nigella damascena was examined and compared using scanning electron microscopy and light microscopy, and the putative relationships of Helleborus and Nigella were analysed. H. thibetanus and N. damascena share some features of floral phyllotaxis and development of the sepals, petals, stamens and carpels, which are also found in other members of Ranunculaceae. However, they differ strongly in the number and degree of fusion of the carpels: in H. thibetanus, the two carpels are slightly united at the base, whereas, in N. damascena, the gynoecium is syncarpous and the five carpels are united throughout the ovary. Differences are also noted in petal development. The blade of the young petal of H. thibetanus develops two bulges which become connate and then fuse with the blade at the sides, developing more quickly than the blade and forming a tubular petal. In N. damascena, a single ridge is formed on the petal blade which develops into the smaller adaxial labium of the bilabiate petal, whereas the blade itself develops into the larger abaxial labium bearing two pseudonectaries. The outermost stamens are delayed in development in Helleborus, but not in Nigella. Although the results from our investigation are preliminary, differences in floral development characters suggest that Helleborus and Nigella may not be closely related and possibly support placement into separate tribes. © 2011 The Linnean Society of London, Botanical Journal of the Linnean Society, 2011, 166, 431–443.