First steps towards a floral structural characterization of the major rosid subclades
First steps towards a floral structural characterization of the major rosid subclades
复制标题
DOI：
10.1007/s00606-006-0444-7
复制
发表时间：
2006-09-01
影响因子：
1.9
通讯作者：
Matthews, M. L.
中科院分区：
文献类型：
--
作者：
Endress, P. K.;Matthews, M. L.
我们对蔷薇属几个较大分支的比较研究和1400多篇关于蔷薇花的原始出版物的调查表明，花的结构特征在不同程度上支持分子系统发育研究提出的蔷薇属的超群关系。然而，由于许多明显的关系尚未得到很好的解决，结构性支持也仍然是试探性的。一些在本研究中引起兴趣的特征在早期的超常研究中没有被考虑到。花类结构支持最强的是十字花科（Brassicales, Malvales, Sapindales），这反映了系统发育分析的强大支持。在结构上支持较少的是COM （Celastrales, Oxalidales, Malpighiales）和固氮（Cucurbitales, Fagales, Fabales, Rosales）的fabids分支，它们在系统发育分析中也只有很弱的支持。姐妹对Cucurbitales + Fagales和Malvales + Sapindales在结构上只有弱支撑，整个fabids在目前的花结构资料中没有明确的支撑。然而，一个额外的分组，COM进化支加上malvids，共享一些有趣的特征，但在系统发育分析中并没有作为一个进化支出现。因此，在分子系统发育分析中（无论证据多么薄弱），似乎eurosid中最深的分裂——fabids和malvids之间的分裂——与目前的结构数据不匹配。胚珠的特征包括珠被的厚度、珠心的厚度和胚珠的弯曲程度，这些特征在更高层次的关系中显得特别有趣，应该进一步探讨。虽然感兴趣的特征在一个大进化支的水平上不一定是稳定的，但它们确实在特定进化支中显示出相当大的集中，而在其他进化支中则是罕见或缺乏的。这可能被视为这一特征在这一群体中进化的一种特殊趋势，或者被视为一种突触性（或两者的结合）。
A survey of our own comparative studies on several larger clades of rosids and over 1400 original publications on rosid flowers shows that floral structural features support to various degrees the supraordinal relationships in rosids proposed by molecular phylogenetic studies. However, as many apparent relationships are not yet well resolved, the structural support also remains tentative. Some of the features that turned out to be of interest in the present study had not previously been considered in earlier supraordinal studies. The strongest floral structural support is for malvids (Brassicales, Malvales, Sapindales), which reflects the strong support of phylogenetic analyses. Somewhat less structurally supported are the COM (Celastrales, Oxalidales, Malpighiales) and the nitrogen-fixing (Cucurbitales, Fagales, Fabales, Rosales) clades of fabids, which are both also only weakly supported in phylogenetic analyses. The sister pairs, Cucurbitales plus Fagales, and Malvales plus Sapindales, are structurally only weakly supported, and for the entire fabids there is no clear support by the present floral structural data. However, an additional grouping, the COM clade plus malvids, shares some interesting features but does not appear as a clade in phylogenetic analyses. Thus it appears that the deepest split within eurosids-that between fabids and malvids - in molecular phylogenetic analyses (however weakly supported) is not matched by the present structural data. Features of ovules including thickness of integuments, thickness of nucellus, and degree of ovular curvature, appear to be especially interesting for higher level relationships and should be further explored. Although features of interest are not necessarily stable at the level of a large clade, they do show a considerable concentration in particular clades and are rare or lacking in others. This may be viewed as a special trend for this feature to evolve in this group or to be conserved as a synapomorphy (or a combination of both).