Phylogeny and Androecial Diversification of Loasaceae

系统分类学研究包括物种和属之间的系统发育或系谱关系的研究，以及对谱系中形态多样性如何产生的分析。华盛顿州立大学的Larry Hufford博士正在研究花的形态多样性，特别是在植物科Loasaceae中复杂的雄蕊结构，重点研究大属Mentzelia（闪亮的星星）和Loasoideae亚科。虽然在物种数量上是一个相对较小的科（约325个），但其组成的分类群具有广泛的雄蕊数、形态和变异。分类学家利用许多这些特征作为特征来识别该科内的不同属，但与其他特征证据的差异表明，这些雄蕊特征中的一些可能在枇杷科内以多种方式进化了多次，可能与授粉的变化有关。利用从绣球科和其他相关科中约114个物种和许多外群分类群的核和叶绿体基因收集的DNA序列数据，将对该家族内部的进化关系进行独立评估。以健全的系统发育树为框架，可以在形态学变化方向可以合理推断的密切相关物种之间进行比较。在花的发育过程中，组织和器官水平的变化将通过光学和扫描电子显微镜进行研究，以确定在枇杷科中观察到的不同雄蕊结构中是否存在相似或不同的器官形成模式。花形的研究是将系统发育分析与形态转化相结合的早期阶段。特别是，该研究试图解决在枇杷科植物中，什么是明显的花在同质化（以前分开的器官的单一生长）和幼体化（早期和截断的发育，保留了幼体特征，作为花的最终“成体”形式）方面的趋势。

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).