The University of Tokyo · Agricultural and Biological Sciences
Professor Joel H. Nitta's research lab specializes in plant evolutionary biology, with a focus on ferns and lycophytes. The lab integrates molecular phylogenetics, integrative taxonomy, and ecological community ecology to study the evolutionary diversification, life cycle transitions, and ecological roles of ferns. A central theme is the use of DNA barcoding and next-generation sequencing to resolve species boundaries, understand reproductive modes, and track community dynamics across life stages—particularly the often-overlooked gametophyte generation. The lab also investigates how major ecological shifts, such as the rise of angiosperm forests, influenced fern evolution and adaptation, especially in epiphytic lineages.
Figures are computed from collected data and may differ slightly.
Ferns, with about 12,000 species, are the second most diverse lineage of vascular plants after angiosperms. They have been the subject of numerous molecular phylogenetic studies, resulting in the publication of trees for every major clade and DNA sequences from nearly half of all species. Global fern phylogenies have been published periodically, but as molecular systematics research continues at a rapid pace, these become quickly outdated. Here, we develop a mostly automated, reproducible, open
Premise of research. Ferns (monilophytes) and lycophytes are unique among land plants in having two independent life stages: the gametophyte generation, which is generally small, cordiform, and short-lived, senescing after fertilization, and the sporophyte generation, which is considered the dominant, long-lived portion of the life cycle produced following fertilization. In many species of epiphytic ferns, however, the gametophyte generation is capable of sustained vegetative growth, and some ar
Abstract Ferns are the only major lineage of vascular plants that have nutritionally independent sporophyte (diploid) and gametophyte (haploid) life stages. However, the implications of this unique life cycle for fern community ecology have rarely been considered. To compare patterns of community structure between fern sporophytes and gametophytes, we conducted a survey of the ferns of the islands of Moorea and Tahiti (French Polynesia). We first constructed a DNA barcode library (plastid rbcL a
Abstract The Moorea Biocode seeks to compile an integrative taxonomy based on morphological, ecological, and molecular data for the entire macrobiota of the island of Moorea, French Polynesia. As a case study exploring the utility of selected molecular data for species identification within this integrative taxonomic framework, chloroplast DNA from three regions ( rbcL, trnSGG, trnH‐psbA ) were sequenced for all species of filmy ferns (Hymenophyllaceae) known from Moorea. The relative utility of
The C. minutum species complex is a reticulate network including multiple diploid lineages and their stabilized hybrid crosses. Additional sampling focused on reproductive mode and ploidy level is needed to delimit diploid species and hybrids.
The expansion of angiosperm-dominated forests in the Cretaceous and early Cenozoic had a profound effect on terrestrial biota by creating novel ecological niches. The majority of modern fern lineages are hypothesized to have arisen in response to this expansion, particularly fern epiphytes that radiated into the canopy. Recent evidence, however, suggests that epiphytism does not correlate with increased diversification rates in ferns, calling into question the role of the canopy habitat in fern
Our integrative approach reveals previously undetected patterns and drivers of biodiversity in the ferns of Japan. Future conservation efforts should recognize that threats can vary by biodiversity metric and consider multiple metrics when establishing conservation priorities.
Abstract Ferns and lycophytes are unique among land plants in having sporophyte (diploid) and gametophyte (haploid) generations that can grow independently of each other. While most studies of fern ecology focus on the more visible sporophytic stage, the gametophyte is critically important, as it is the sexual phase of the life cycle. Yet, fern gametophytes have long been neglected in field studies due to their small size and cryptic morphology. DNA barcoding is a powerful method that can be use
Biodiversity has typically been quantified using species richness, but this ignores evolutionary history. Due to the increasing availability of robust phylogenies, methods have been developed that incorporate phylogenetic relationships into quantification of biodiversity. CANAPE (categorical analysis of neo‐ and paleo‐endemism) is one such method that can provide insight into the evolutionary processes generating biodiversity. The only currently available software implementing CANAPE is Biodiver
Floristic surveys are crucial to the conservation of biodiversity, but the vast majority of such surveys are limited to listing species names, and few take into account the evolutionary history of species. Here, we combine classical taxonomic and molecular phylogenetic (DNA barcoding) approaches to catalog the biodiversity of pteridophytes (ferns and lycophytes) of the Nectandra Cloud Forest Reserve, Costa Rica. Surveys were carried out over three field seasons (2008, 2011, and 2013), resulting
A new hybrid microsoroid fern, Microsorum × tohieaense (Microsorum commutatum × Microsorum membranifolium) from Moorea, French Polynesia is described based on morphology and molecular phylogenetic analysis. Microsorum × tohieaense can be distinguished from other French Polynesian Microsorum by the combination of sori that are distributed more or less in a single line between the costae and margins, apical pinna wider than lateral pinnae, and round rhizome scales with entire margins. Genetic evid
Open papers in the app to read, cite, and organize with AI.
