Structure and development of flowers and inflorescences in Peraceae and Euphorbiaceae and the evolution of pseudanthia in Malpighiales.
Structure and development of flowers and inflorescences in Peraceae and Euphorbiaceae and the evolution of pseudanthia in Malpighiales.
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DOI：
10.1371/journal.pone.0203954
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发表时间：
2018
期刊：
影响因子：
3.7
通讯作者：
Demarco D
中科院分区：
文献类型：
--
作者：
Gagliardi KB;Cordeiro I;Demarco D
假花器是锦葵目大戟科和Peraceae的退化紧凑花序，具有独立进化的特征。为了分析这一假设，即不同的假杯在Malpighiales中发现有非同源的发展步骤，我们研究了花序和花的发展在三个Malpighiales属，目前这种类型的花序Dalechampia（铁苋菜亚科/大戟科），大戟属（大戟科/大戟科），和Pera（Peraceae）-并比较它们的Joannesia（巴豆亚科/大戟科），不存在假杯。使用光学显微镜和扫描电子显微镜分析花序和花。Dalechampia和Euphorbia具有先雌先熟的两性假花团，Dalechampia具有单性花被，Euphorbia具有无被花。Pera有单性假丹花，雄花有退化的花萼，雌花无被被。Joannesia花是非常明显的，当比较pseudanthia花，因为它们是由所有的轮，没有减少。在发育的早期阶段，假丹花中形成的第一个结构是不同系列的苞片，包括外苞片、总苞片和总苞片。花原基几乎与总苞同时发生。虽然形态不同，但各属的花序早期分枝模式基本一致，且分枝的数量和伸长受雌花发育的影响。我们认为，不同的假丹花是通过花序轴上的花轮减少和花的重组，特别是雌花和雄花的位置和分枝的伸长或缩短的过程进化而来的。顶生花的性别是发育的关键，即，雌核发育对假雄蕊的生长有很大影响，减少了轴的分枝和伸长。
Pseudanthia are reduced and compact inflorescences which apparently had independent evolution in Euphorbiaceae and Peraceae within Malpighiales. In order to analyze the hypothesis that the different pseudanthia found in Malpighiales have non-homologous developmental steps, we studied the inflorescence and flower development in the three Malpighiales genera that present this type of inflorescence–Dalechampia (Acalyphoideae/Euphorbiaceae), Euphorbia (Euphorbioideae/Euphorbiaceae), and Pera (Peraceae)–and compared them to that of Joannesia (Crotonoideae/Euphorbiaceae), which does not present a pseudanthium. Inflorescences and flowers were analyzed using light microscopy and scanning electron microscopy. Dalechampia and Euphorbia have protogynic bisexual pseudanthia, with unisexual perianthed flowers in Dalechampia, and achlamydeous flowers in Euphorbia. Pera has unisexual pseudanthia and the male flowers have a vestigial calyx and the female flowers are achlamydeous. Joannesia flowers are very distinct when compared to the pseudanthia flowers, as they are composed of all the whorls and there is no reduction. In the early stages of development, the first structures to be formed in the pseudanthia are the different series of bracts, including outer, involucral and involucel bracts. The floral primordia are initiated almost simultaneously with the involucre. Although the different morphology, the early inflorescence followed the same branching pattern in all studied genera, and the number and elongation of the branches were affected by the early female flower development in the terminal position. We suggest that the different pseudanthia evolved via process of floral whorl reduction and reorganization of flowers in the inflorescence axes, especially the position of female and male flowers and elongation or shortening of the branches. The sex of the terminal flower is a developmental key, i.e., the protogynic development deeply affects the pseudanthia growth, reducing the ramification and elongation of the axes.
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影响因子：
3
作者：
Prenner G;Rudall PJ
通讯作者：
Rudall PJ
影响因子：
2.1
作者：
ARMBRUSTER, WS;WEBSTER, GL
通讯作者：
WEBSTER, GL
影响因子：
3
作者：
Cacho, N. Ivalu;Berry, Paul E.;Baum, David A.
通讯作者：
Baum, David A.
影响因子：
1.1
作者：
Gagliardi, Karina Bertechine;Rosado, Aline;Albiero, Adriana Lenita Meyer
通讯作者：
Albiero, Adriana Lenita Meyer
影响因子：
4.2
作者：
Endress, Peter K.;Davis, Charles C.;Matthews, Merran L.
通讯作者：
Matthews, Merran L.