Zea systematics: ribosomal ITS evidence

Abstract

Ribosomal internal transcribed spacer (ITS) sequences were used to evaluate the phylogenetics of Zea and Tripsacum. Maximum likelihood and polymorphism parsimony were used for phylogenetic reconstructions. Zea ITS nucleotide diversity was high compared to other plant species, but approximately equivalent to other maize loci. Coalescence of ITS alleles was rapid relative to other nuclear loci; however, there was still much diversity within populations. Zea and Tripsacum form a clade clearly differentiated from all other Poaceae. Four Zea ITS pseudogenes were identified by phylogenetic position and nucleotide composition. The phylogenetic position of Z. mays ssp. huehuetenangensis was clearly established as basal to the other Z. mays. The ITS phylogeny disfavored a Z. luxurians and Z. diploperennis clade, which conflicted with some previous studies. The introgression of Z. mays alleles into Z. perennis and Z. diploperennis was also established. The ITS data indicated a near contemporary divergence of domesticated maize and its two closest wild relatives.

Phylogenetics of Andropogoneae (Poaceae: Panicoideae) Based on Nuclear Ribosomal Internal Transcribed Spacer and Chloroplast trnL–F Sequences

“…5) trees. It includes Tripsacum and Zea and is consistent with analyses of morphology (Kellogg and Watson 1993), ITS (Buckler and Holtsford 1996;Hodkinson et al 2002a), GBSSI (Mathews et al 2002), ndhF (Spangler et al 1999;Giussani et al 2001;Mathews et al 2002), PHYB (Mathews et al 2002), and tb1 (Lukens and Doebley 2001). Zea is also monophyletic in our study, as well as in previous studies (Buckler and Holtsford 1996;Mason-Gamer et al 1998;Lukens and Doebley 2001;Hodkinson et al 2002a).…”

Evolutionary events in Lilium (including Nomocharis, Liliaceae) are temporally correlated with orogenies of the Q–T plateau and the Hengduan Mountains

“…Second, the coalescence of organelle DNA may be four times faster than in nuclear genes (Moore, 1995). Some reports suggest that ITS evolves much faster than chloroplast DNA, but the cases are few and have been recognized as special ones (Buckler and Holtsford, 1996;Sang et al, 1997). Therefore, it is unlikely that lineage sorting of nuclear genes had been completed before the divergences of the incongruent clades from their common ancestor, while polymorphisms in chloroplast genes were retained in their common ancestors.…”

Linajes de angiospermas endémicas en México: zonas de alto endemismo para la conservación

“…In the Acanthaceae, nine genera and a clade within Ruellia are endemic to Mexico (Daniel, 1993;Tripp, 2010). In addition, among the more remarkable endemic groups of Mexico are clades of Bursera (Rzedowski et al, 2005;De-Nova et al, 2012), Agave and groups nested within this genus such as Manfreda, Polianthes and Prochnyanthes (García-Mendoza, 1995;Rocha et al, 2006, the section Physodium in Melochia (Dorr & Barret, 1989), a clade in the Zea diploperennis group (Poaceae) (Buckler & Holtsford, 1996), and a clade of Yucca within the Sarcocarpa group (Pellmyr et al, 2007). Fouquieria and Leucophyllum are arid land groups in Mega-Mexico (Henrickson & Flyr, 1985;Schultheis & Baldwin, 1999).…”