Dissertation Research: The Systematics and Evolution of Jaltomata (Solanaceae)

PIS提出了一项关于Jaltomata的分类、系统发育关系模式和进化过程的研究。茄科的一种新热带草本到耐寒的属。这种鲜为人知且在分类学上令人困惑的物种特别令人感兴趣，因为它正在墨西哥作为一种水果作物逐步驯化；其他几个物种的水果和根茎也被人类消费。PI将构建一个基于叶绿体DNA的系统发育图。基于这一严格构建的系统发展史，将测试形态和核型进化以及生物地理学的独立派生模式。他们还将探索繁殖系统的进化。Jaltomata特别适合于研究进化过程和模式，原因有几个。属的界限是一个具有挑战性的问题；一些工作者将管状花的Jaltomata种保留为Hebecladus，而Saracha和Physalis的种被视为Jaltomata。不同物种之间(习性、兽皮、花冠形状和颜色等)存在较大的形态多样性。因此，该群致力于形态进化的研究，因为它涉及到系统发育、染色体进化、海拔/栖息地偏好的进化以及繁殖系统的进化。该属包括多种繁育系统，如自交、兼性自交和专性异交。

The PIs proposed a study of the taxonomy, pattern of phylogenetic relationships and evolutionary processes in Jaltomata. A neotropical, herbaceous to suffrutescent genus of the Solanaceae. One species of this poorly understood and taxonomically confused genus is of particular interest because it is undergoing progressive domestication in Mexico as a fruit crop; fruits and root-stocks of several other species are also consumed by humans. The PIs will construct a chloroplast DNA-based phylogeny. Based on this rigorously constructed phylogeny, independently derived patterns of morphological and karyotypical evolution and biogeography will be tested. They will also explore evolution of breeding systems. Jaltomata is especially suitable for the study of evolutionary process and pattern for several reasons. Generic boundaries present a challenging problem; some workers retain the tubular flowered Jaltomata species as Hebecladus, and species of Saracha and Physalis have been treated as Jaltomata. There is much morphological diversity among species (habit, vestiture, corolla shape and color, etc.). The group, therefore, lends itself to the study of morphological evolution as it relates to phylogeny, chromosomal evolution, the evolution of altitude / habitat preference and breeding system evolution. The genus includes a diversity of breeding systems such as autogamy, facultative autogamy, and obligate outcrossing.