Are mitochondrial genes useful for the analysis of monocot relationships?

Abstract

A phylogenetic analysis of monocots and related dicots was conducted, using a four-gene matrix consisting of two genes from the plastid genome (matK and rbcL) and two from the mitochondrial genome (atpA/atp1 and cob). The taxon sample includes 101 monocots and 36 dicots, and all four genes were sampled for all 137 taxa. Jackknife support was assessed for clades resolved by the four-gene analysis, and compared to support for the same clades by each of the four three-gene subset matrices, in order to quantify the degree to which each gene contributed to or detracted from support for each clade. Instances of positively and negatively correlated support for clades by genes of the same and different genomes were observed. In particular, the placement of Acorus within a clade that also includes Tofieldiaceae, Araceae, and Alismatales s.s., as opposed to its frequent placement as sister of all other monocots, is supported by atpA and matK. The results indicate that genes from the mitochondrial genome provide a unique test of relationships that have been inferred with plastid-encoded genes.

A Functional Phylogenomic View of the Seed Plants

“…Similarly, increased sampling of the alismatids and aroids will help confirm the position of Acorus within the angiosperms. Our findings of Acorus as sister to all other monocots, supports most analyses conducted with single and multiple gene trees [38]–[41], except for those that include atp A, which in some instances, place Acorus within the Alismatales aroids plus alismatids [42]–[44]. Within the rosids, the topology of MP-30 departs from that of APG III, by placing the Sapindales ( Citrus and relatives) with the rosids I, versus rosids II in APG III and in our MP-full and ML-30 analyses.…”

Fossil fruit of Cocos L. (Arecaceae) from Maastrichtian-Danian sediments of central India and its phytogeographical significance

“…Arecaceae/Palmae, the family of Cocos, is monophyletic in origin and has been placed within the commelinid clade of the monocotyledons (Chase et al 2006, Davis et al 2006. Palms are an important and characteristic component of tropical rainforest ecosystems having a pantropical distribution (Couvreur et al 2011).…”

Systematic Placement of Dasypogonaceae Among Commelinid Monocots: Evidence from Flowers and Fruits

“…Chase et al 2000) and morphological (e.g., Rudall et al 1999), have rejected these relationship hypotheses, instead linking Hanguana with either Zingiberales or Commelinales. Combined multigene analyses for monocots have placed Dasypogonaceae either as sister to Poales sensu lato (Chase et al 2006;Davis et al 2006), sister to Zingiberales plus Commelinales (Graham et al 2006), or sister to palms (Givnish et al 2010;Barrett et al 2012). The currently unresolved relationship between Dasypogonaceae and these three major groups represents one of the primary remaining questions in monocot phylogenetics, currently being addressed by the ongoing Assembling the Monocot Tree of Life project.…”

“…In particular, silica bodies are present in almost all commelinids, but absent from all non-commelinids except orchids (Chase et al 2006). B, Dasypogonaceae sister to Poales, palms sister to Zingiberales+Commelinales (Davis et al 2006). C, Dasypogonaceae sister to palms (Chase et al 1995b).…”

“…3). Molecular analyses have variously placed them as sister to all other commelinids (Davis et al 2004), closely related to palms (Chase et al 1995a, b;Givnish et al 2010;Barrett et al 2012), sister to Commelinales/Zingiberales (Graham et al 2006) or sister to Poales sensu lato (Chase et al 2006;Davis et al 2006). This paper reviews existing systematic data on Dasypogonaceae, and presents new data on floral structure and ontogeny.…”