How to build distylous flowers: comparative floral development and evolution of distylous species across the angiosperms
How to build distylous flowers: comparative floral development and evolution of distylous species across the angiosperms
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DOI：
10.1002/ajb2.1363
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发表时间：
2019-09-20
影响因子：
3
通讯作者：
Cohen，James
中科院分区：
文献类型：
--
作者：
Cohen，James
PremiseDistyly是一个以两种花型为特征的植物育种系统，其花药和柱头的位置相互对应，至少在27个被子植物科中已知，使其成为趋同进化的一个很好的例子。花发育的模式产生不同的花药和柱头高度在每个形态的各种方式仍然在很大程度上未开发的发展和进化perspectives.MethodsIn 15种代表至少12个起源的distyly，高度和长度的花器官在每个形态在整个发展过程中进行了检查，使用光学显微镜。花器官发育的模式进行了测定和比较种间。家庭级别的distylous物种和亲属的adhergenies重建，和祖先herkogamy的模式resolved.ResultsDifferences在花发育之间的形态导致12种模式，导致花药和柱头的位置特征distyly。Distylous物种进化的祖先与不同类型的herkogamy，与方法herkogamy和缺乏herkogamy解决most frequent.ConclusionsSeven的12种模式的花发育已知的只有一个物种，与其他三个模式之间的近亲对。最常见的花发育模式，从至少7个属，涉及花药高度，不同的intermorph生长速率和柱头高度，生长速率不同的变形之间只有在以后的发展。这一模式在唇形科亚纲中很常见，表明该分类群内的花发育是渠道化的。在二型种中，相同类型的祖先herkogamy可以产生不同的花发育模式。
PremiseDistyly, a plant breeding system characterized by two floral morphs that have reciprocal positioning of anthers and stigmas, is known from at least 27 angiosperm families, making it an excellent example of convergent evolution. The various manners in which patterns of floral development produce the distinct anther and stigma heights in each morph remain largely unexplored from developmental and evolutionary perspectives.MethodsIn 15 species representing at least 12 origins of distyly, heights and lengths of floral organs in each morph throughout development were examined using light microscopy. Patterns of floral organ development were determined and compared among species. Family‐level phylogenies of distylous species and relatives were reconstructed, and patterns of ancestral herkogamy were resolved.ResultsDifferences in floral development between morphs resulted in 12 patterns leading to the anther and stigma positions characterizing distyly. Distylous species evolved from ancestors with different types of herkogamy, with approach herkogamy and lack of herkogamy resolved most frequently.ConclusionsSeven of the 12 patterns of floral development are known from only one species, with three other patterns described among pairs of close relatives. The most common pattern of floral development, described from at least seven genera, involves for anther heights, distinct intermorph growth rates and for stigma heights, growth rates that differ between morphs only during later development. This pattern is common among subclass Lamiidae, suggesting canalized development within the taxon. Among distylous species, the same type of ancestral herkogamy can give rise to different patterns of floral development.