Phylogeny of South African Gnaphalieae (Asteraceae) based on two noncoding chloroplast sequences

Abstract

The Gnaphalieae are a group of sunflowers that have their greatest diversity in South America, Southern Africa, and Australia. The objective of this study was to reconstruct a phylogeny of the South African Gnaphalieae using sequence data from two noncoding chloroplast DNA sequences, the trnL intron and trnL/trnF intergenic spacer. Included in this investigation are the genera of the Gnaphalieae from the African basal groups, members of the subtribes Cassiniinae, Gnaphaliinae, and Relhaniinae, and African representatives from the large Old World genus Helichrysum. Results indicate that two Gnaphaloid genera, Printzia and Callilepis, should be excluded from the Gnaphalieae. In most trees the Relhaniinae s.s. (sensu stricto) and some of the basal taxa comprise a clade that is sister to the remainder of the tribe Gnaphalieae. The Relhaniinae, which are restricted to Africa, are not a monophyletic group as presently circumscribed, nor are the South African members of Helichrysum, the Cassiniinae and Gnaphaliinae. There is general agreement between our molecular analysis and that of morphology, particularly in the terminal branches of the trees.

Evidence for convergent evolution among phylogenetically distant rare species of Tetratheca (Elaeocarpaceae, formerly Tremandraceae) from Western Australia

“…Determination of consistent differences in DNA sequences is a complementary tool to morphological analysis for assessing taxon distinctness. The most frequently sequenced regions of the plant genome for the investigation of species-level relationships are the internal transcribed spacer (ITS) of nuclear rDNA (see Baldwin et al 1995 for a review; Bena et al 1998aBena et al , 1998b and the trnL-trnF spacer in the chloroplast genome (see Sang et al 1997 for a review; Bayer et al 2000), and an analysis of these regions was undertaken to investigate relationships within the T. aphylla-T. paynterae-T. harperi group of 'leafless' species from the Koolyanobbing area and the taxonomic status of the newly identified, unclassified collections affiliated with these species. A molecular systematic study of these taxa can also be used to investigate the phylogenetic signal of putatively significant morphological characters, such as ovule number and the leafless condition, as well as elucidate the biogeographical relationships between these rare ironstone endemics and their affiliates.…”

Phylogenetic analysis of Mangifera from central region of Sumatra using trnL-F intergenic spacer

“…The trnL-F region of cpDNA is naturally conservative with a low rate evolution (Bayer et al 2000). This region is more varied than the sequences of the coding region (Bayer et al 2000). This analysis is expected to show higher nucleotide variation in closely related species or the extent intraspecies, which will discover the distinguishing characteristics among species in the genus of Mangifera.…”

“…Markers of chloroplast DNA (cpDNA), that are widely used is trnL-F intergenic spacer, are a part of the cpDNA non-coding region, the region which more varied than the coding region, so this makes it more suitable to be used in uncovering the evolutionary relationships among the lower level of taxa (Bayer et al 2000). Some studies in non-coding regions of chloroplast showed a higher variation and it was frequently mutated (Baldwin et al 1995) in the forms of transversion, transition, insertion, and deletion.…”

“…Therefore, this platform is commonly used in the phylogenetic studies because they are easily isolated, purified, characterized and cloned. The trnL-F region of cpDNA is naturally conservative with a low rate evolution (Bayer et al 2000). This region is more varied than the sequences of the coding region (Bayer et al 2000).…”

A review of genetic analyses of hybridisation in New Zealand

“…Some putative hybrids have been tested by rigorous morphological analysis (McKenzie 2001 ;McKenzie et al 2003McKenzie et al , 2004 and others are supported by the display of additive combinations of nrDNAITS sequences (Smissen et al 2003;Smissenunpubl.). The intergeneric status of many of the hybrids in the Raouîia alliance reflects marked morphological divergence between many of the species involved rather than phylogenetic relationships, as generic boundaries in the Gnaphalieae have not been aligned with robust phylogenetic analyses (the papers of Bayer et al 2000Bayer et al , 2002Breitwieser et al 1999 not withstanding). Within the Raouîia alliance trans-specific plastid DNA polymorphism is prominent (Smissen et al 2004) and may be the result of chloroplast introgression, but to date, no population level studies have detected contemporary gene flow.…”