Phylogeny of <I>Leavenworthia</I> and <I>Selenia</I> (Brassicaceae)

Abstract

The present study aimed to develop a robust, extensively sampled phylogenetic hypothesis across all species in Leavenworthia and Selenia using chloroplast (psbj-petA) and nuclear encoded (nrDNA ITS and LUMINIDEPENDENS) DNA sequence data. Parsimony and maximum likelihood methodologies were employed. Strong maximum likelihood bootstrap and parsimony jackknife support were recovered for the monophyly of the sister pair Leavenworthia plus Selenia and for the respective monophyly of each genus. Leavenworthia and Selenia are hypothesized to have diverged in the Ozark Mountains and results from an analysis of branch lengths leading to Leavemvorthia and Selenia clades are consistent with Leavenworthia having diversified more recently than Selenia. Polyploidy and extensive aneuploidy complicate the interpretation of chromosomal evolution within and between these genera. Comparative results from phylogenetic analyses indicate that L. aurea and L. texana are hybrids with a shared set of putative parents. Lastly, patterns of diversification within Leavenworthia appear to have included a minimum of three transformations from self-incompatible to self-compatible systems.

Diverse genome organization following 13 independent mesopolyploid events in Brassicaceae contrasts with convergent patterns of gene retention

“…Leavenworthia (eight species) is confined to New World and the available chromosome counts mapped on a phylogenetic tree (Urban and Bailey, ) suggest that n = 11 is a descending dysploidy from n = 15, and most likely both chromosome numbers were derived from the primary hexaploid genome with n = 24 chromosomes (2 n = 6 x = 48). Considering that Leavenworthia and Selenia (five species) form a well‐defined monophyletic group, with some species of Leavenworthia and Selenia co‐occurring, it can be assumed that the WGT pre‐dates the divergence of two sister genera and that it contributed to diversification and species radiation within this North American Cardamineae subclade.…”

Costs of selfing prevent the spread of a self‐compatibility mutation that causes reproductive assurance

“…Transitions to self-compatibility from self-incompatibility are common in Leavenworthia (Rollins 1963;Lloyd 1965). Of the eight species recognized, phylogenetic evidence suggests a minimum of three origins of self-compatibility within the genus (Herman et al 2012;Urban and Bailey 2013). Within Leavenworthia alabamica, Rollins (1963) identified multiple infraspecific races based on differences in floral morphology and selfcompatibility among populations.…”

Molecular phylogenetics of tribe Eudemeae (Brassicaceae) and implications for its morphology and distribution

“…The family is distributed worldwide (except Antarctica) and is well represented in the Southern Hemisphere, with 374 native species in South America (Al-Shehbaz, unpubl.). Based on the extensive molecular phylogenies published over the past eight years (e.g., Al-Shehbaz and Warwick, 2007;Alexander et al, 2010Alexander et al, , 2013Bailey et al, 2006Bailey et al, , 2007Beilstein et al, 2006Beilstein et al, , 2008Couvreur et al, 2010;Franzke et al, 2009Franzke et al, , 2011German et al, 2009German et al, , 2011Goodson et al, 2011;Hall et al, 2011;Jordon-Thaden et al, 2010;Karl and Koch, 2013;Khosravi et al, 2007Khosravi et al, , 2008Khosravi et al, , 2009aKoch, 2012;Koch et al, 2007Koch et al, , 2008Koch et al, , 2010Rešetnik et al, 2013;Salariato et al, 2013a;Urban and Bailey, 2013;Warwick and Hall, 2009;Warwick et al, 2007Warwick et al, , 2008Warwick et al, , 2010Warwick et al, , 2011Yue et al, 2009;Zhao et al, 2010), Al-Shehbaz (2012a) recognized 49 tribes in the Brassicaceae. Of these, the Cremolobeae R.Br., Schizopetaleae R.Br.…”