Phylogeny and Androecial Diversification of Loasaceae

Hufford系统学研究包括研究物种和属之间的系统发育或系谱关系，以及分析形态多样性是如何在谱系中产生的。华盛顿州立大学的拉里·赫福德博士正在研究罗汉果科植物在花型上的形态多样性，特别是复杂的雄蕊构型，重点是大属Mentzelia(炽热的星星)和Loasoideae亚科。虽然在种的数量上是一个相对较小的科(总共约325个)，但Loasaceae包括具有广泛的雄蕊数量、构型和变型的分类群。分类学家使用这些特征中的许多特征作为特征来识别该科中不同的属，但与其他特征证据的差异表明，其中一些雄蕊特征在Loasaceae内进化了多次，可能以多种方式进化，可能与授粉的转移有关。将使用从核和叶绿体基因收集的DNA序列数据对该科内的进化关系进行独立评估，这些DNA序列数据涉及约114个物种和绣球花科和其他相关科的许多外群分类群。以强健的系统发育树为框架，可以对亲缘关系密切的物种进行比较，从而合理地推断形态变化的方向。将用光学和扫描电子显微镜研究花发育过程中的组织和器官水平的变化，以确定在萝卜科中观察到的各种雄蕊构型是相似的还是不同的器官形成模式。黄豆科植物花型的研究是系统发育分析与形态转化融合的早期阶段。具体地说，这项研究试图解决Loasaceae内部在联合组织(以前独立的器官的单一生长)和幼化(早期和截断的发育，将幼体特征保留为花中最终的“成体”形式)方面的明显花趋势。

0075249Hufford Systematics research includes the study of phylogenetic or genealogical relationships among species and genera, and the analysis of how morphological diversity arises within lineages. Dr. Larry Hufford at Washington State University is studying morphological diversity in floral forms, especially in the complex staminal configurations, in the plant family Loasaceae, emphasizing the large genus Mentzelia (blazing stars) and the subfamily Loasoideae. Although a relatively small family in terms of number of species (ca. 325 total), Loasaceae comprise taxa with a wide range of stamen numbers, configurations, and modifications. Taxonomists have used many of these features as characters to recognize distinct genera within the family, but discrepancies with other character evidence have suggested that some of these staminal characters have evolved multiple times, possibly in multiple ways, within Loasaceae, perhaps in association with shifts in pollination. An independent assessment of evolutionary relationships within the family will be made using DNA sequence data collected from nuclear and chloroplast genes, for ca. 114 species and for numerous outgroup taxa in the Hydrangeaceae and other related families. With a robust phylogenetic tree as framework, comparisons can be made between closely related species where the direction of morphological change can reasonably be inferred. Tissue- and organ-level changes in flower development will be studied with light and scanning electron microscopy, to determine whether similar or different patterns of organ formation underlie the various staminal configurations observed in Loasaceae. The study of floral form in Loasaceae represents an early step in the fusion of phylogenetic analysis with morphological transformation. In particular, the study attempts to resolve within Loasaceae what are apparent floral trends in synorganization (unitary growth of formerly separate organs) and juvenilization (early and truncated development that preserves juvenile features as the final "adult" form in the flower).