Horsetails and ferns are a monophyletic group and the closest living relatives to seed plants

Abstract

Most of the 470-million-year history of plants on land belongs to bryophytes, pteridophytes and gymnosperms, which eventually yielded to the ecological dominance by angiosperms 90 Myr ago. Our knowledge of angiosperm phylogeny, particularly the branching order of the earliest lineages, has recently been increased by the concurrence of multigene sequence analyses. However, reconstructing relationships for all the main lineages of vascular plants that diverged since the Devonian period has remained a challenge. Here we report phylogenetic analyses of combined data--from morphology and from four genes--for 35 representatives from all the main lineages of land plants. We show that there are three monophyletic groups of extant vascular plants: (1) lycophytes, (2) seed plants and (3) a clade including equisetophytes (horsetails), psilotophytes (whisk ferns) and all eusporangiate and leptosporangiate ferns. Our maximum-likelihood analysis shows unambiguously that horsetails and ferns together are the closest relatives to seed plants. This refutes the prevailing view that horsetails and ferns are transitional evolutionary grades between bryophytes and seed plants, and has important implications for our understanding of the development and evolution of plants.

Rate heterogeneity among lineages of tracheophytes: Integration of molecular and fossil data and evidence for molecular living fossils

“…We also evaluate variation caused by method of estimation and calibration point. We estimate the ages, with confidence intervals, of major clades of tracheophytes, using (i) a tree based on four genes and morphology (21), (ii) data from four genes singly and combined, and (iii) multiple calibration points representing well-substantiated dates in the fossil record. We also test for rate constancy among lineages and heterogeneity of rates among genes and codon positions in protein-coding genes and evaluate sensitivity of age estimates to branch lengths inferred by maximum parsimony (MP) and maximum likelihood (ML), the effectiveness of NPRS relative to an assumption of rate constancy, and the correspondence of molecular-based estimates to the fossil record.…”

Purification, cDNA cloning, and characterization of LysM-containing plant chitinase from horsetail (Equisetum arvense)

“…One is EaChiA, the other is PrChiA. Pryer et al 32) showed that there are three monophyletic groups of extant vascular plants: seed plants, lycophytes, and ferns (seedless vascular plants without lycophytes). This refutes the notion that ferns are transitional evolutionary grades between bryophytes and seed plants.…”

Monilófitas da Estação Ecológica do Panga, Uberlândia, Estado de Minas Gerais, Brasil: Dennstaedtiaceae, Dryopteridaceae, Gleicheniaceae, Hymenophyllaceae e Lindsaeaceae

“…De acordo com Smith et al (2006), Hymenophyllaceae é monofilética e está constituída por nove gêneros, 600 espécies e dois grandes clados formados por espécies tricomanóides e himenofilóides (Pryer et al 2001, Smith et al 2006.…”