Molecular phylogeny of subgenus Polypompholyx (Utricularia; Lentibulariaceae) based on three plastid markers: diversification and proposal for a new section

Abstract

Phylogenetic relationships among all of the 47 recognised species and 10 putative new taxa of Utricularia subgenus Polypompholyx, were assessed using maximum parsimony and Bayesian inference analyses of DNA sequences representing the plastid rps16 intron, trnL–F intron and spacer regions and the trnD–T intron. We found strong jackknife and posterior-probability support for a monophyletic subgenus Polypompholyx and a sister relationship between the sections Polypompholyx+Tridentaria and Pleiochasia. Within the section Pleiochasia, are two well-supported major clades, each containing three supported clades. Our S-DIVA biogeographic analysis, using five major Australian drainage basins and New Zealand as geographic areas, estimated two early vicariance events between south-western and north-western mainland regions, corresponding with known periods of increased aridity at 15 and 6million years ago. Subsequent dispersal events were estimated between northern and south-eastern Australia, with recent dispersal of species from south-western regions to the south-east and New Zealand occurring between 4million and 1million years ago. There were 28 speciation events inferred within the north-western region, followed by 9 for the south-western and south-eastern regions, indicating that the north-western monsoonal savanna habitats are a biodiversity hotspot for the lineage. We also show the evolutionary shifts in growth habit, and show that lifecycle corresponds strongly with shifts in seasonality between temperate and monsoonal regions. On the basis of our molecular phylogenetic results and morphology, we here designate a new sectional ranking for subgenus Polypompholyx.

Six new species of Utricularia (Lentibulariaceae) from Northern Australia

“…Recognition as distinct species is supported by morphological (this paper) and molecular phylogenetic results (Jobson et al 2017). Utricularia albertiana and U. magna were previously thought to be Kimberley forms Utricularia sp.…”

“…Polypompholyx (Lehm.) P. Taylor sensu Muller and Borsch (2005) (Taylor 1989;Reut and Jobson 2010;Jobson et al 2003Jobson et al , 2017. This paper describes an additional six species found in the Kimberley region of Western Australia, and / or the 'Top End' of the Northern Territory; all but one are apparently restricted to one or other of these two regions.…”

“…The monsoon tropics of Australia is an area of globally significant species diversity of the carnivorous plant genus Utricularia L., with more than 49 species known (Taylor 1989;Jobson and Baleeiro 2015;Jobson et al 2017). Although some species have widespread extralimital distributions, or are widespread across northern Australia, a high proportion of species are geographically localised, particularly those belonging to subg.…”

“…Accessions representing five of the taxa were included in a recent molecular phylogeny that showed four of the species, namely Utricularia albertiana R.W. Jobson (Jobson et al 2017). All of these species are from the Northern Kimberley region of Western Australia, with U. bidentata also found at Edith River in the Northern Territory.…”

“…Utricularia albertiana and U. magna were previously thought to be Kimberley forms Utricularia sp. Bearded (R.W.Jobson 2308) sensu Jobson et al (2017).…”