The Utility of Nuclear ITS, a LEAFY Homolog Intron, and Chloroplast atpB-rbcL Spacer Region Data in Phylogenetic Analyses and Species Delimitation in Isoëtes

By S. B. Hoot, W. Taylor. 2001

87 citations recorded by the source corpus.

Abstract Despite its ancient origins, its worldwide distribution, and adaptation to diverse habitats, Isoëtes has a highly conserved morphology. This feature has made it difficult to resolve species and species relationships using morphological characters. In this paper, we report the utility of nucleotide sequences from the nuclear internal transcribed spacer (ITS) regions, chloroplast atpB/rbcL intergenic spacer region, and second intron of a LEAFY (LFY) homolog for identifying species relationships, delimiting basic diploid species, and determining hybrid origins. Variation in the ITS regions and atpB/rbcL spacer is most useful at the family level in Isoëtes and the LFY second intron is appropriate at the species and population level. The tree resulting from an analysis of the combined nuclear ITS and chloroplast atpB/rbcL spacer contains three major well supported clades (bootstrap ≥ 99%): an Old-World/California clade (I. abyssinica, I. longissima, I. velata, I. nuttallii, and I. orcuttii), an Asian/Australian clade (I. taiwanensis, I. japonica, I. kirkii, and I. drummondii), and a poorly resolved clade consisting of nine North American species. To further resolve and delimit the North American species, a combination of the LEAFY second intron and ITS data was used. The resulting consensus tree has limited resolution, supporting the hypothesis that the North American species complex radiated rapidly. The combination of LFY and ITS data provided numerous characters, both substitutions and indels, that are useful in species delimitation and identification of cryptic species. ITS sequence data, through additive banding and sequence misalignment, is also useful in confirming interspecific hybrids and determining their parental origins.

Subfields: Ecology, Evolution, Behavior and Systematics, Molecular Biology

View Paper: https://www.semanticscholar.org/paper/8422e017bdd54eb50389edd5884f43619b697392

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Ecology, Evolution, Behavior and Systematics

In Molecular Biology

Citations in the corpus

Phylogenetics of Polygonaceae with an Emphasis on the Evolution of Eriogonoideae (2008, background): “The second intron of LEAFY has been used in analyses of evolutionary relationships at low taxonomic levels (Frohlich and Meyerowitz 1997; Hoot and Taylor 2001; Oh and Potter 2003; Grob et al. 2004; Oh and Potter 2005).”
Molecular Phylogenetic Relationships and Morphological Evolution in the Heterosporous Fern Genus Marsilea (2007, background): “Phylogeny of Isoëtes (Lycopsida): resolving basal relationships using rbcL sequences.”
Cryptic speciation between Juniperus deltoides and Juniperus oxycedrus (Cupressaceae) in the Mediterranean (2005, background): “Hoot and Taylor (2001) found cryptic species of Isoetes using ITS, LEAFY and atpBerbcL sequence data.”