Dissertation Research: Heterochrony in the Dry Tropics: Moringa

点击翻译按钮获取中文摘要

9801128 Raven/Schaal/Olsen Moringa, the only genus of the horseradish tree family (Moringaceae), spans an unparalled range of form and geography, from massive, water-storing "bottle trees" in Madagascar and Namibia, to slender trees in Arabia and India, to tiny tuberous herbs in northeastern Africa. The highest diversity of plant form is thought to occur in the dry tropics, but the mechanisms that have produced this diversity is little studied. In this doctoral dissertation research, Peter Raven, Barbara Schaal and doctoral student Mark Olsen will examine the role of historical changes in the timing of developmental events ("heterochrony") in producing the array of shapes among species of Moringa. The research will employ a novel combination of techniques to follow the development of wood and flowers, both in wild plants and in those maintained under carefully controlled conditions of cultivation. The developmental studies will be interpreted in the context of an hypothesis of the historical ("phylogenetic") relationships of the different Moringa species that the researchers will infer from an analysis of morphological and molecular (gene sequence) characters. The research should contribute to an understanding of how plants with recent common histories may diversify in form and function to thrive in different environmental conditions. This award includes a contribution from the Africa, Near East and South Asia program, Division of International Programs.