Phylogeny of gymnosperms inferred fromrbcL gene sequences

Hasebe, Mitsuyasu; Kofuji, Rumiko; Itô, Motomi; Kato, Mikio; Iwatsuki, Kunio; Ueda, Kazumitsu

doi:10.1007/bf02489441

Cited by 59 publications

(36 citation statements)

References 21 publications

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“…1). This confirmed previous results based on nuclear 18S rRNA and 26S rRNA sequences (8) as well as rbcL sequences (9). Given that Ginkgo and Ephedra (a Gnetales) did not branch out before the angiosperm-conifer-cycad lade (Fig.…”

Section: Resultssupporting

confidence: 91%

“…Given that Ginkgo and Ephedra (a Gnetales) did not branch out before the angiosperm-conifer-cycad lade (Fig. 1), a result also reported from morphological and molecular studies (8,9,49,50), the earliest divergence among extant seed plants is likely to be represented by the split between the conifer-cycad lineage and the angiosperm lineage (node A in Fig. 1).…”

Section: Resultssupporting

confidence: 60%

“…Although phylogenetic analysis of 18S rRNA and 26S rRNA sequences and cladistic analysis of morphological characters placed Ephedra and other Gnetales as a sister group to the angiosperms (8,49,50), results from rbcL sequences are more variable, with the Gnetales as either a sister group to the angiosperms (10) or nested within the gymnosperms (9).…”

Section: Resultsmentioning

confidence: 99%

“…Phylogenetic analysis of conserved gene sequences from extant plant taxa has contributed tangibly to our understanding of the early diversification of seed plants (8)(9)(10)(11). Chloroplast and nuclear gene sequences have also been used to construct molecular clocks and to estimate the times for key events in the evolutionary history of flowering plants (12).…”

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confidence: 99%

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Chloroplast and nuclear gene sequences indicate late Pennsylvanian time for the last common ancestor of extant seed plants.

Savard

Strauss

et al. 1994

Proc. Natl. Acad. Sci. U.S.A.

134

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We have estimated the time for the last commoancor of extant seed plants by using molecular clocks constructed from the ofthe chloroplastic gene coding for the large subunit of ribulose-1,5-blphosphate carboxylase/oxygenase (rbcL) and the nuclear gene coding for the snail subunit of rRNA (Rrnl8). Phylogenetic analyses of nucleodde sequences indicated that the earliest divergence of extant seed plants is likely represented by a split between conufer-cycad and ansperm linea . Relative-rate tests were used to assess homogeneity of substution rates among lineages, and annual anglosperms were found to evolve at a faster rate than other taxa for rbcL and, thus, these sequences were excluded from construction of molecular clocks. Five distinct molecular cocks were calibrated using substitution rates for the two genes and four divergence times based on fossil and published molecular cock estimates. The five mated times for the last common ancestor of extant seed plants were in agreement with one another, with an average of 285 million years and a range of 275-290 million years. This implies a subsantily more recent ancestor of all extant seed plants than suggsed by some theories of plant evolution.Although progymnosperms are accepted as the ancestral group to all seed plants, the time when the five groups of extant seed plants (cycads, conifers, Ginkgo, Gnetales, and angiosperms) shared their last common ancestor is unclear because of uncertainty about ancestor-descendant relationships between progymnosperms and seed plants (1, 2). Beck (2-5), although not discussing angiosperms, proposed that the two main lineages of gymnosperms, coniferopsids (conifers, Ginkgo, and Gnetales) and cycadopsids (cycads), diverged independently from two lineages of the progymnosperms, with coniferopsids from Archaeopteridales and cycads from Aneurophytales. Because Archaeopteridales and Aneurophytales appeared in the Middle Devonian, Beck's hypothesis implies that the two gymnosperm lineages diverged about 375 million years (Myr) ago. Alternatively, Rothwell (6, 7) hypothesized that the two gymnosperm lineages both evolved from Aneurophytales via the seed fern complex, suggesting a more recent diversification of extant seed plants.Phylogenetic analysis of conserved gene sequences from extant plant taxa has contributed tangibly to our understanding of the early diversification of seed plants (8-11). Chloroplast and nuclear gene sequences have also been used to construct molecular clocks and to estimate the times for key events in the evolutionary history of flowering plants (12).However, before applying molecular clocks to date evolutionary events, approximate constancy of evolutionary rate over time needs to be established (13) by using procedures for assessing rate homogeneity over taxa (14,15) or over lineages (16).Here we estimate the time when extant seed plants shared their last common ancestorby using molecular clocks derived from nucleotide sequences of the chloroplast gene coding for the large subunit of ribulose-1,5-bispho...

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Section: Resultssupporting

confidence: 91%

Section: Resultssupporting

confidence: 60%

Section: Resultsmentioning

confidence: 99%

mentioning

confidence: 99%

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Chloroplast and nuclear gene sequences indicate late Pennsylvanian time for the last common ancestor of extant seed plants.

Savard

Strauss

et al. 1994

Proc. Natl. Acad. Sci. U.S.A.

134

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“…Troitsky et al (1991) used ribosomal RNA and also found extant gymnosperms to be monophyletic, but they too sampled taxa thinly; although a total of 11 genera were used (three cycads, two gnetophytes, Ginkgo and five conifers), and only up to six genera from the whole set were included in each analysis. Likewise, Hasebe et al (1992) used plastid rbcL sequences on a small set of taxa and similarly found extant gymnosperms to be monophyletic. The first broadly sampled molecular phylogenetic study to examine gymnosperm relationships was that of Chaw et al (1997), and like the other studies they found extant gymnosperms to be sister to the angiosperms.…”

Section: Introductionmentioning

confidence: 99%

A new classification and linear sequence of extant gymnosperms

Christenhusz¹,

Reveal²,

Farjon³

et al. 2011

Phytotaxa

396

239

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A new classification and linear sequence of the gymnosperms based on previous molecular and morphological phylogenetic and other studies is presented. Currently accepted genera are listed for each family and arranged according to their (probable) phylogenetic position. A full synonymy is provided, and types are listed for accepted genera. An index to genera assists in easy access to synonymy and family placement of genera.

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The golden decade of molecular floral development (1990-1999): A cheerful obituary

Theißen¹,

Saedler

1999

Dev. Genet.

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Phylogeny of gymnosperms inferred fromrbcL gene sequences

Cited by 59 publications

References 21 publications

Chloroplast and nuclear gene sequences indicate late Pennsylvanian time for the last common ancestor of extant seed plants.

Chloroplast and nuclear gene sequences indicate late Pennsylvanian time for the last common ancestor of extant seed plants.

A new classification and linear sequence of extant gymnosperms

The golden decade of molecular floral development (1990-1999): A cheerful obituary

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