An assessment of old and new DNA sequence evidence for the paraphyly of Banksia with respect to Dryandra (Proteaceae)

Abstract

Banksia (80 spp.; Proteaceae) has undergone extensive speciation and adaptive radiation on the island continent of Australia. Its members range from prostrate shrubs in the dry, infertile sandplains to 25 m tall trees in the loams of river margins, and they display striking variation in their fire survival strategies and floral and foliar morphologies. We examine the weight of both previously published (most trnL intron, trnL/F spacer, and rpl16 intron data) and new (matK, atpB, and waxy data, as well as most ITS data) DNA sequence evidence for the paraphyly of Banksia with respect to a monophyletic Dryandra (93 spp.). The nuclear waxy gene appears to be at two loci in the Proteaceae, and sequences presumably from the same locus resolve Banksia as paraphyletic with respect to Dryandra. The waxy and combined chloroplast DNA (cpDNA) data reject the monophyly of Banksia at a threshold of P = 0.05 using the winning sites and Kishino–Hasegawa tests. We consider this result and the repeated placement of Dryandra in the same clade (/Cryptostomata) of Banksia with each separate analysis of the DNA datasets (cpDNA, ITS, and waxy), to be strong molecular support for the paraphyly of Banksia with respect to Dryandra. The morphological synapomorphy of beaked follicles for /Cryptostomata (including Dryandra) reinforces this conclusion. We argue that realignment of taxa to produce one or more monophyletic genera is best attained by moving the taxa of Dryandra to Banksia. This would produce an easily recognised genus Banksia with four morphological synapomorphies. It would also probably confer some of the research attention garnered by the adaptive radiation of Banksia to the under-studied taxa of Dryandra, for Dryandra makes the radiation of Banksia even more remarkable.

Time‐calibrated phylogeny of the woody Australian genus Hakea (Proteaceae) supports multiple origins of insect‐pollination among bird‐pollinated ancestors

“…Data for 70 of these species are presented here for the fi rst time; data from the rest fi rst were presented by Mast and Givnish (2002) or Mast et al (2005Mast et al ( , 2008. The 75 species include 55 (of 149) species of Hakea , one species from each of the other 11 genera in tribe Embothrieae, one species from each of the other three tribes in subfamily Grevilleoideae, one species from each of the other four subfamilies in Proteaceae, and one species from each of the other two families of Proteales been implicated in fl oral pollination ( Proctor and Yeo, 1973 ).…”

“…Following Mast et al (2008) , we cloned all the nDNA regions but not the cpDNA regions. We sequenced the rpl16 intron following procedures described by Mast et al (2005) .…”

Climate change, plant migration, and range collapse in a global biodiversity hotspot: theBanksia(Proteaceae) of Western Australia

“…Finally, to ensure that models captured the full realized niche of species under study (rather than arbitrary limits such as political borders), we focus on those species of the genus Banksia (including Dryandra ) considered endemic to Western Australia. We include species of the genus Dryandra as Banksia was recently found to be paraphyletic with respect to Dryandra (Mast et al , 2005) and a new taxonomic arrangement transferring Dryandra to Banksia has been initiated (Mast & Thiele, 2007). Here forth, we use the term Banksia to describe both Banksia and Dryandra species.…”

Evolution of a hotspot genus: geographic variation in speciation and extinction rates in Banksia (Proteaceae)

“…Based on molecular evidence [14], a recent taxonomic revision [15] sunk the former genus Dryandra into Banksia , forming a large new genus of 170 species. The majority of these are endemic to the SWBP, but Banksia have dispersed throughout the southern, eastern and northern parts of Australia (Figure 1).…”