Molecular data place Hydnoraceae with Aristolochiaceae

Abstract

Utilization of molecular phylogenetic information over the past decade has resulted in clarification of the position of most angiosperms. In contrast, the position of the holoparasitic family Hydnoraceae has remained controversial. To address the question of phylogenetic position of Hydnoraceae among angiosperms, nuclear SSU and LSU rDNA and mitochondrial atp1 and matR sequences were obtained for Hydnora and Prosopanche. These sequences were used in combined analyses that included the above four genes as well as chloroplast rbcL and atpB (these plastid genes are missing in Hydnoraceae and were hence coded as missing). Three data sets were analyzed using maximum parsimony: (1) three genes with 461 taxa; (2) five genes with 77 taxa; and (3) six genes with 38 taxa. Analyses of separate and combined data partitions support the monophyly of Hydnoraceae and the association of that clade with Aristolochiaceae sensu lato (s.l.) (including Lactoridaceae). The latter clade is sister to Piperaceae and Saururaceae. Despite over 11 kilobases (kb) of sequence data, relationships within Aristolochiaceae s.l. remain unresolved, thus it cannot yet be determined whether Aristolochiaceae, Hydnoraceae, and Lactoridaceae should be classified as distinct families. In contrast to most traditional classifications, molecular phylogenetic analyses do not suggest a close relationship between Hydnoraceae and Rafflesiaceae. A number of morphological features is shared by Hydnoraceae and Aristolochiaceae; however, a more resolved phylogeny is required to determine whether these represent synapomorphies or independent acquisitions.

Fossil calibration of Magnoliidae, an ancient lineage of angiosperms

“…Moore et al (2007) used it to define a minimum age of 113 Ma, Soltis et al (2008) Doyle and Endress (2000), with the exclusion of several taxa (eudicots, Piperales, Nymphaeales, monocots, Austrobaileya, Schisandraceae, and Illicium), placed Lovellea wintonensis in one most parsimonious position sister to all Laurales excluding Calycanthaceae (Dettmann et al, 2009). This "core Laurales" clade was well supported in previous studies (Soltis et al, , 2000a(Soltis et al, , 2000b(Soltis et al, , 2011Qiu et al, 1999Qiu et al, , 2000Qiu et al, , 2005Qiu et al, , 2006Qiu et al, , 2010Renner, 1999Renner, , 2004Doyle and Endress, 2000;Savolainen et al, 2000;Zanis et al, 2002Zanis et al, , 2003Nickrent et al, 2002;Hilu et al, 2003). Relationships within the clade based on the morphological analysis were not identical to those found in molecular or combined morphological and molecular analyses (Doyle and Endress, 2000), but they are consistent in supporting the monophyly of the Hernandiaceae-Lauraceae-Monimiaceae clade (though with the addition of Siparunaceae) and the position of Atherospermataceae and Gomortegaceae as outgroups to this clade (though as two successive branches rather than a clade).…”

“…Although Magnoliidae have a global distribution extending into the temperate zones of both hemispheres, most of their diversity occurs in tropical areas. This group has been supported as monophyletic by the great majority of molecular phylogenetic studies (Qiu et al, 1999(Qiu et al, , 2005(Qiu et al, , 2006(Qiu et al, , 2010Soltis et al, 1999Soltis et al, , 2000aSoltis et al, , 2000bSoltis et al, , 2007Soltis et al, , 2011Mathews andDonoghue, 1999, 2000;Savolainen et al, 2000;Graham and Olmstead, 2000;Zanis et al, 2002Zanis et al, , 2003Nickrent et al, 2002;Borsch et al, 2003;Hilu et al, 2003;Jansen et al, 2007;Moore et al, 2007Moore et al, , 2010Burleigh et al, 2009). Although the majority of the relationships among families of Magnoliidae are well established, the exact positions of Hydnoraceae and Magnoliaceae and the relationships among Hernandiaceae, Lauraceae, and Monimiaceae are still debated (Figure 1; Massoni et al, 2014).…”

Phylogenetic Analyses of Basal Angiosperms Based on Nine Plastid, Mitochondrial, and Nuclear Genes

“…Acorus and Ceratophyllum were the only two genera for which two species each were sampled. Only two families of basal angiosperms were not included, Gomortegaceae (Renner 1999) and Hydnoraceae (Nickrent et al 2002), because of many missing data entries. Most of the terminals consist of sequences derived from a single species (and frequently the same DNA sample) and occasionally from different species of the same genus (tables 1, 2).…”

“…The past 20 years have witnessed significant progress in our understanding of the phylogeny of basal angiosperms from analyses of molecular and nonmolecular data (Dahlgren and Bremer 1985;Donoghue and Doyle 1989;Loconte and Stevenson 1991;Martin and Dowd 1991;Hamby and Zimmer 1992;Taylor and Hickey 1992;Chase et al 1993;Qiu et al 1993Qiu et al , 2000Qiu et al , 2001Soltis et al 1997Soltis et al , 2000Nandi et al 1998;Hoot et al 1999;Donoghue 1999, 2000;Parkinson et al 1999;Renner 1999;Soltis et al 1999a;Barkman et al 2000;Doyle and Endress 2000;Graham and Olmstead 2000b;Savolainen et al 2000;Nickrent et al 2002;Zanis et al 2002Zanis et al , 2003Borsch et al 2003;Hilu et al 2003;Lö hne and Borsch 2005). Specifically, it has become increasingly clear that Amborella, Nymphaeaceae, and Austrobaileyales (sensu APG II 2003) represent the earliestdiverging lineages of extant angiosperms.…”

Mitochondrial DNA sequences reveal the photosynthetic relatives of Rafflesia , the world's largest flower

“…The use of mt sequences to study parasitic plant phylogeny seems promising because the holoparasitic angiosperm family Hydnoraceae was recently placed by using a combination of mtDNA with plastid and nuclear sequences (51). One reason for the utility of mtDNA for studying the phylogeny of holoparasites is that the evolutionary dynamics governing these sequences seem to be similar in parasitic plants and their free-living relatives.…”