PEET: Monographic and Phylogenetic Studies of Simple Thalloid Hepatics (Jungermanniopsida, Metzgeriidae)

Southern Illinois University At Carbondale, Carbondale IL

Investigators

Abstract

9977961 Raymond Stotler and Barbara Crandall-Stotler The two goals of this project in the Partnerships for Enhancing Expertise in Taxonomy are to resolve the taxonomic perplexities of the Metzgeriidae, a plant group commonly referred to as the simple thalloid liverworts, and in the process to train a new generation of skilled experts in hepaticology, i. e., the study of liverworts. The Metzgeriidae are the geologically oldest group of bryophytes, with fossil representatives dating back to the beginning of terrestrial plant colonization, about 400 million years ago. Today, they are cosmopolitan in distribution but with their greatest diversification in the tropics. In addition to playing a major role in the nutrient cycles of tropical ecosystems, liverworts synthesize a myriad of biologically active compounds that have pharmaceutical potential. Tapping this potential, however, necessitates that the diversity of these poorly known, understudied plants be inventoried and classified and that fundamental features of their reproductive biology be elucidated. To this end, the research plan of this project includes the following: a taxonomic survey of the morphological diversity of the suborders Pelliineae and Pallaviciniineae, represented in existing herbarium collections; field investigations of population structure of select taxa of these suborders in North America and Puerto Rico; a collecting expedition to New Zealand and Tasmania; electron-microscopic anatomical studies of conducting strand differentiation within plants of these suborders; and the generation of nuclear and chloroplast DNA sequences for phylogenetic analyses of the Metzgeriidae. Monographic studies of the Pelliineae and Pallaviciniineae are an expansion of the monographic and phylogenetic studies of a current PEET project focused on the Fossombroniineae, another basal suborder of the Metzgeriidae. In the production of the monograph, nomenclatural type specimens will be located and verified, based on their protologues, specimen loans will be arranged with all major herbaria, worldwide, and a combination of quantitative and qualitative characters will be assessed, using both SEM and optical photomicroscopy. Additional data from morphometric analyses of variation patterns, field studies, molecular sampling and anatomical studies will then be used to refine species definition. In addition, a robust molecular phylogeny of the entire Metzgeriidae will be produced. Through a combination of formal courses in systematics, seminars, workshops, and involvement in project research, a minimum of three doctoral students and one postdoctoral fellow will be trained in modern monography. Research responsibilities will be partitioned according to taxa, rather than technique, so each trainee will learn all of the methods being applied to the monograph. Research training opportunities will also be provided for two undergraduate students per year. Computer-assisted methods of data storage and retrieval, image processing, data analysis and information dissemination will be used at all stages in the project, with electronic access to project results provided through the World Wide Web. Electronic products will include an illustrated nomenclator, web-accessible specimen and literature databases, and interactive keys. The completed monographs will be archived on CD-ROM disks.