DNA sequences from three genomes reveal multiple long-distance dispersals and non-monophyly of sections in Australasian Plantago (Plantaginaceae)

Abstract

In our recent paper (Tay et al. 2010), several errors arose in Figs 5 and 6, mostly at the drafting stage: we neglected a polytomy in both figures; the tree topology in Fig. 6 was incorrect; the names of seven terminal taxa were associated with the wrong branches in Fig. 6; and P. euryphylla was spelled incorrectly in Fig. 5. The figures presented here correct these errors.Additionally, we have updated the data presented by including the diploid chromosome number of P. daltonii (Brown 1981).Fortunately, the discussion and conclusions of the original paper are still consistent with the revised figures. Abstract. We examined the geographic origins and taxonomic placements of New Zealand and Australian Plantago (Plantaginaceae) by using molecular phylogenetic data. Plantago comprises over 200 species distributed worldwide. Analyses of three markers from the nuclear (ITS), chloroplast (ndhF-rpl32) and mitochondrial (coxI) genomes showed that the New Zealand species form three distinct, well supported clades that are not each others' closest relatives, and were each derived relative to the sampled Australian species. Therefore, at least three long-distance directional dispersal events into New Zealand can be inferred for Plantago, likely from Australian ancestors. This result differs from the biogeographic pattern often reported for New Zealand plant genera of a single dispersal event followed by rapid radiation, and may be attributed to ready biotic dispersal of mucilaginous seeds and habitat similarities of the Australasian species. Molecular dating placed the arrival time and diversification of the New Zealand species between 2.291 and 0.5 million years ago, which coincides with the geological dates for the uplift of mountain ranges in New Zealand. The mitochondrial DNA substitution rate of the Australasian clade relative to the rest of the genus is discussed, as well as implications of the non-monophyly of sections Oliganthos, Mesembrynia and Plantago within subgenus Plantago.

New World Origins of Southwest Pacific Gesneriaceae: Multiple Movements Across and Within the South Pacific

“…However, subtropical Coronanthereae might have been unsuited for the cool climate and extreme seasonality of Antarctica, which finally became inhospitable to woody plants ;15 Ma (Hill and Scriven 1995). The findings in numerous molecular studies now support the hypothesis that current biotic patterns in the southern Pacific are influenced by dispersal (Swenson and Bremer 1997;Hurr et al 1999;Wagstaff et al 2000Wagstaff et al , 2002Mummenhoff et al 2001;Gemmill et al 2002;Winkworth et al 2002b;Howarth et al 2003;Nepokroeff et al 2003;Smissen et al 2003;Berry et al 2004;Clement et al 2004;Mummenhoff 2004;Albach et al 2005;Bartish et al 2005;Cronk et al 2005;Motley et al 2005;Meudt and Simpson 2006;Clark et al 2008Clark et al , 2009Pfeil and Crisp 2008;Smith et al 2008;Tay et al 2010). The inference of dispersal has been most obvious for species on oceanic islands of recent origin but less so for those on continental islands.…”

“…Hebe (Wagstaff et al 2002, as Hebe and relatives), Fuchsia (Berry et al 2004, in Australia as fossils only), Ourisia (Meudt and Simpson 2006), Oreobolus (Seberg 1988), Tetrachondra (Wagstaff et al 2000), and Abrotanella (Swenson and Bremer 1997). However, in the past 20 years, molecular ages (Wagstaff et al 2002(Wagstaff et al , 2007Smissen et al 2003;Pfeil and Crisp 2008;Tay et al 2010) have indicated that many southern disjunct plant groups are too recent for their distributions to be explained by Gondwanic vicariance. Further, cladogram topologies often do not match the order of vicariance events (see Pole 1994Pole , 2001Linder and Crisp 1995;and McGlone et al 2001 for overviews).…”

New chromosome counts in New Zealand species ofPlantago(Plantaginaceae)

“…Finally, we report 2n012 for a naturalized plant from which Tay et al (2010a) previously obtained an ITS DNA sequence (as 'P. sp.…”

“…Plantago) (Rahn 1996). When chromosome number was mapped onto a recent molecular phylogeny of Australasian species of these sections, it was shown that polyploid series have evolved at least four times in the Australasian group (Tay et al 2010a). Tay et al (2010a) also concluded that sections as currently circumscribed are not all monophyletic.…”

“…When chromosome number was mapped onto a recent molecular phylogeny of Australasian species of these sections, it was shown that polyploid series have evolved at least four times in the Australasian group (Tay et al 2010a). Tay et al (2010a) also concluded that sections as currently circumscribed are not all monophyletic. We believe that detailed cytological studies will play a key role in resolving the historically difficult taxonomy of the New Zealand species of Plantago, as was the case with their southern South American counterparts (Rahn 1984).…”