Molecular Evolution of the Internal Transcribed Spacers (ITS1 and ITS2) and Phylogenetic Relationships among Species of the Family Cucurbitaceae

doi:10.1006/mpev.1997.0465

Molecular Phylogenetics and Evolution

Volume 9, Issue 2, April 1998, Pages 204-219

https://doi.org/10.1006/mpev.1997.0465 Get rights and content

Abstract

Phylogenetic relationships of different members of the family Cucurbitaceae were estimated from sequences of the internal transcribed spacer (ITS1 and ITS2) regions of the nuclear ribosomal RNA genes. Twenty-six species of different genera belonging to different tribes and several subtribes were analyzed. The whole ITS regions were amplified by PCR technique and cloned, and three to five different clones of each species were sequenced; for some species PCR products were sequenced directly. ITS1 and ITS2 regions are slightly variable in length, with each length appearing genus-specific. A substitution rate of 3.62 × 10⁻⁹substitutions per site per year was calculated assuming 40 MYA separation time. Phylogenetic relationships inferred from ITS sequences of some species is in agreement with morphological data, but deviations to the taxonomic classification were also observed. A polyphyletic origin of the New World species must be considered. In the genusCucurbitadifferent “types” of ITS sequences within one species exist, possibly due to the high frequency of introgression during domestication or due to polyploidization events; in contrast, low intraspecific variability was detectable in the genusCucumis,indicating different stages of speciation.

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^☆: Sequence data from this article have been deposited with the EMBL/GenBank Data Libraries under Accession Nos. AF006764–AF006819 and AF013298–AF013359.

^☆☆: A. WaltersP. G. Alderson

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Regular ArticleMolecular Evolution of the Internal Transcribed Spacers (ITS1 and ITS2) and Phylogenetic Relationships among Species of the Family Cucurbitaceae☆,☆☆

Abstract

Mol. Phylogenet. Evol.

J. Mol. Biol.

Trends Genet.

Gene

Methods Companion Methods Enzymol.

Mol. Phylogenet. Evol.

J. Mol. Biol.

J. Mol. Biol.

Mol. Phylogenet. Evol.

On morphology and taxonomy of the generaCucumisMelo

Feddes Repertorium

A phylogenetic analysis of the aureoidSenecioAsteraceae

Plant Syst. Evol.

Molecular phylogenetics ofCalycadenia

Am. J. Bot.

The ITS region of nuclear ribosomal DNA: A valuable source of evidence on angiosperm phylogeny

Ann. Missouri Bot. Gard.

Biology and Utilization of the Cucurbitaceae

Compositional patterns in vertebrate genomes: Conservation and change in evolution

J. Mol. Evol.

The mosaic genome of warm blooded vertebrates

Science

Maintenance of genetic homogeneity in systems with multiple genomes

Genet. Res.

Five major nuclear ribosomal repeats represent a large and variable fraction of the genomic DNA ofPicea rubensP. mariana

Mol. Biol. Evol.

Zea

Mol. Biol. Evol.

Persistent nuclear ribosomal DNA sequence polymorphism in theAmelanchier

Mol. Biol. Evol.

Molecular drive: A cohesive mode of species evolution

Nature

Conversion in vitro ofCucumis metuliferusC. anguria

Plant Tissue Culture and its Agricultural Applications

Confidence limits on phylogenies: An approach using the bootstrap

Evolution

Comparison of the ribosomal RNA genes in four closely related Cucurbitaceae

Plant Syst. Evol.

Ribosomal RNA as a phylogenetic tool in plant systematics

Characterization of a new prominent satellite DNA ofCucumis metuliferusCucumis

Euphytica

Organization of highly repetitive satellite DNA of two Cucurbitaceae species (Cucumis meloCucumis sativus

Nucleic Acids Res.

Organization and length heterogeneity of plant ribosomal RNA genes

The relationship between satellite desoxyribonucleic acid, ribosomal ribonucleic acid gene redundancy, and genomic size in plants

Plant Physiol.

An outline classification of the Cucurbitaceae

Notes on Cucurbitaceae including a proposed new classification of the family

Kew. Bull.

Variation and inheritance of ribosomal DNA inPinus sylvestris

Heredity

Comparison of phylogenetic hypothesis among different data sets in dwarf dandelions (Krigia

Plant Sys. Evol.

A simple method for estimating evolutionary rate of base substitutions through comparative studies of nucleotide sequences

J. Mol. Evol.

Molecular evolution of the intergenic spacer in the nuclear ribosomal RNA genes of Cucurbitaceae

J. Mol. Evol.

Differential homogenization and amplification of two satellite DNAs in the genusCucurbita

J. Mol. Evol.

Regular Article
Molecular Evolution of the Internal Transcribed Spacers (ITS1 and ITS2) and Phylogenetic Relationships among Species of the Family Cucurbitaceae☆,☆☆