Phylogenetic relationships within the tribe Malveae (Malvaceae, subfamily Malvoideae) as inferred from ITS sequence data

Abstract

Phylogenetic relationships among genera of tribe Malveae (Malvaceae, subfamily Malvoideae) were reconstructed using sequences of the internal transcribed spacer (ITS) region of the 18S-26S nuclear ribosomal repeat. Newly generated sequences were combined with those available from previous generic level studies to assess the current circumscription of the tribe, monophyly of some of the larger genera, and character evolution within the tribe. The ITS data do not support monophyly of most generic alliances as presently defined, nor do the data support monophyly of several Malveae genera. Two main well-supported clades were recovered, which correspond primarily to taxa that either possess or lack involucral bracts, respectively. Chromosomal evolution has been dynamic in the tribe with haploid numbers varying from n = 5 to 36. Aneuploid reduction, hybridization, and/or polyploidization have been important evolutionary processes in this group.

Phylogeny and Character Evolution in the New Zealand Endemic Genus Plagianthus (Malveae, Malvaceae)

“…Taxon Sampling-This study builds upon our earlier phylogenetic studies of New Zealand Malveae ( Heenan et al 2005 ;Tate et al 2005 ;Wagstaff et al 2010 ) with the addition of chloroplast-encoded sequences to complement the ITS sequences. Our sample included 28 sequences with representatives of all six genera comprising the Plagianthus alliance of Bates (1968) .…”

“…chathamicus from the Chatham Islands). Outgroups included Asterotrichion discolor , Gynatrix pulchella ( Tate et al 2005 ), and one representative from the seven species currently included in Hoheria ( Wagstaff et al 2010 ). We included two herbaceous representatives of Lawrencia sect.…”

“…Lawrencia , and two shrubs included in Lawrencia sect. Selenothamnus ( Tate et al 2005 ); we rooted our analysis along the long-branch leading to these taxa. Voucher information, along with GenBank accession numbers are presented in Appendix 1.…”

“…Recent studies of Wagstaff et al (2010) and Tate et al (2005) suggest that Plagianthus regius (Poit.) Hochr.…”

“…chathamicus (Cockayne) de Lange. Plagianthus and Hoheria also share a haploid chromosome number of n = 21 ( Groves and Hair 1971 ;Dawson and Beuzenberg 2000 ), but chromosome numbers of other members of the Plagianthus alliance remain unknown ( Tate et al 2005 ).…”