Floral Phenology Patterns and Breeding Systems in Thaspium and Zizia (Apiaceae)
Floral Phenology Patterns and Breeding Systems in Thaspium and Zizia (Apiaceae)
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Thaspium 和 Zizia（伞形科）的花物候模式和育种系统
DOI：
10.2307/2418648
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发表时间：
1982
期刊：
影响因子：
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通讯作者：
Anne H. Lindsey
中科院分区：
文献类型：
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作者：
Anne H. Lindsey
在伞形花序中，原生雌化与雄蕊异花的明确模式相一致，在塔斯皮属和齐齐属的单个茎中，花和花序发育的强烈同行性产生了性阶段的改变，促进了这些属植物的强异交系统，尽管它们完全自交。这些物候特征结合自交研究、柱头花粉负荷分析和花粉/胚珠比测定，揭示了部分个体的不完全原型化可使bar- binode和zz . trifoliata的机械自花授粉率达到5-10%，而trioliatum的机械自花授粉率高达20%。一株植物的茎通常不会同步开花，昆虫介导的单株植物茎间的雌雄同体交配可能在种群内造成大量的自交现象。然而，高花粉：胚珠比例和柱头花粉负荷数据表明，在Thaspium和Zizia中存在强烈的异种通婚现象。一个稀疏的文献表明，成员Apiaceae（伞形科）有一个潜在的强异交系统的基础上，在花和花序发育的特征时间。Muller（1883）指出，蜂科植物的原雄蕊二偶制影响了阶段的交替，“因此，在开花的第一个时期，整个群落将花粉撒在访问它的昆虫身上，而在第二个时期，它的柱头暴露出来，以供返回。”类似地，Knuth（1908）评论说伞形植物的性模式，结合明显的原生生殖，有利于
Protogyny, in concert with a well-defined pattern of andromonoecism in umbel inflorescences and strong synchrony of floral and inflorescence develop- ment within individual stalks of Thaspium and Zizia, produces sexual phase alter- nations that promote a strong outcrossing system in plants of these genera despite full self-compatibility. Study of these phenology patterns in conjunction with selfing studies, analysis of stigmatic pollen loads, and determinations of pollen: ovule ratios in 9 populations (including 4 taxa) of Thaspium and Zizia revealed that incomplete protogyny in some individuals allows 5-10% mechanical self-pollination in T. bar- binode and Z. trifoliata and up to 20% mechanical self-pollination in T. trifoliatum. Stalks of one plant do not generally flower synchronously and insect-mediated gei- tonogamy between stalks of a single plant may account for significant amounts of selfing within populations. Strong xenogamy within Thaspium and Zizia is suggested, however, by high pollen: ovule ratios and by stigmatic pollen-load data. A sparse literature suggests that members of Apiaceae (Umbelliferae) have a potential for strong outcrossing systems based on characteristic timing in floral and inflorescence development. Muller (1883) noted that protandrous dichogamy in species of Apiaceae effected phase alterna- tions "so that in the first period of flowering, a whole community dusts with pollen the insects that visit it, and in the second, exposes its stigmas to be dusted in return." Similarly, Knuth (1908) commented that sexual patterns in umbellifers, in combination with well-marked protandry, pro-