The project uses a synergistic approach to understand the biodiversity and evolution of ferns, a major component of the land flora and will focus on a group of tropical ferns within the genus Elaphoglossum. There are more than 600 species of Elaphoglossum and the vast majority of these species are characterized by simple leaves. However, there is a group within Elapholgossum, section Squamipedia, that has 3 species with compound leaves. The project seeks to understand the genetic basis of these diverse leaf morphologies after first discovering the evolutionary relationships among these plants. All the species in Elaphoglossum section Squamipedia will be inventoried and described using field work, herbarium collections and morphological analyses, followed by analysis of DNA sequences that will develop phylogenetic hypotheses. The genetic basis of fern leaf diversity in section Squamipedia will be examined by cloning candidate leaf genes and performing comparative expression and developmental analyses in compound and simple leaved species. These studies are integral for understanding general patterns of leaf evolution and development in land plants.
This study will initiate a collaboration between PI Moran, a systematist, and Co-PI Ambrose, a developmental biologist. This proposal will provide interdisciplinary training for a female postdoctoral associate from Latin America. In connection with the field work, the PI will teach a course on ferns and lycophytes at the Catholic University in Quito, Ecuador. The PI will also work with members of the New York Fern Society on Elaphoglossum morphology. The Co-PI participates in the NYBG summer internship program that provides research experience for high school and undergraduate students. All results of the study will be made publicly available on the Elaphoglossum Pages Web site (http://sweetgum.nybg.org/elaphoglossum/index.php) and in peer-reviewed scientific journals.
, a primarily American tropical group of ferns. The monographic research determed how many species belonged to the group, how to distinguish them, and where they occurred. The phylogenetic study determined the evolutionary relationships among the species. Neither of these researches had ever been done for the group. As a result of the research, three new species were described. The project also examined the leaf developmental genetics of sect. Squamipedia. This was significant because nearly all of the 600 species of Elaphoglossum have simple, entire leaves, but four species of sect. Squamipedia have divided leaves. The phylogenetic study found that divided leaves evolved independently four times in sect. Squamipedia. In other words, the four species with divided leaves did not form an natural evolutionary unit (monophyletic group). This repeated evolution of leaf division was further studied in the laboratory using the methods of developmental genetics. The data gathered allowed for the first time a comparison of the development of fern leaves to that of lycophytes and seed plants. The comparison indicated that lycophyte leaves develop in a way that suggests a different evolutionary origin than the leaves of ferns and seed plants. In particular, evidence was found that lycophyte leaves represent sterilized sporangia. As a result of the project, 15 papers were published in refereed scientific journals. The project trained an undergraduate student from Mount Holyoke University, and of a woman post-doctoral researcher from Latin America. Both women have career paths in biology. Also, in conjunction with field work, a one-week fern course was taught at the Catholic University in Quito, Ecuador.
