Phylogenetic analysis of the Australian Salicornioideae (Chenopodiaceae) based on morphology and nuclear DNA

Abstract

The Salicornioideae Kostel. are distinctive among the Chenopodiaceae Venet. However, their phylogenetic relationships are poorly understood. Analyses of morphological and molecular characters were undertaken to evaluate relationships within the subfamily and to test the monophyly of the endemic Australian genera Halosarcia Paul G. Wilson, Pachycornia Hook.f., Sclerostegia Paul G. Wilson, Tecticornia Hook.f. and Tegicornia Paul G. Wilson. Kalidium Moq. and Halopeplis Bunge ex Ung.-Sternb. of the tribe Halopeplideae were used as outgroup representatives in the morphological analysis and resolved sister to the tribe Salicornieae. Allenrolfea Kuntze; Halocnemum Bieb. and Heterostachys Meyer formed an early branching group sister to a moderately supported clade comprised of the remaining Salicornieae. Only terminal groups of closely related species received significant bootstrap support in this analysis. In contrast, the current tribal classification of the Salicornioideae was not supported in the molecular analysis as Allenrolfea occidentalis Kuntz (tribe Salicornieae) positioned sister to Kalidium foliatum Moq. (tribe Halopeplideae) and the remaining Salicornieae. Three major clades received strong bootstrap support: Microcnemum + Arthrocnemum, Sarcocornia + Salicornia, and the endemic Australian genera. None of the endemic Australian genera was individually supported as monophyletic in either the morphological or the molecular analyses. Subspecies complexes, polyploids and hybrids may contribute to the lack of resolution and apparently high levels of homoplasy in the morphological analysis. A greater understanding of population level processes is required to begin to resolve the phylogeny of this complex group.

Phylogeny, biogeography, systematics and taxonomy of Salicornioideae (Amaranthaceae/Chenopodiaceae) – A cosmopolitan, highly specialized hygrohalophyte lineage dating back to the Oligocene

“…Halosarcia was distinguished from Arthrocnemum by the absence of sclereids in the chlorenchyma and flowers that have only one (abaxial) stamen. Based on a morphological and molecular study of Shepherd & al. (2005b), Shepherd & Wilson (2007) incorporated Halosarcia together with Pachycornia, Sclerostegia and Tegicornia in one genus, Tecticornia.…”

“…Later molecular studies have supported the subfamily status of Salicornioideae (Kadereit & al., 2003(Kadereit & al., , 2006Kapralov & al., 2006;Kadereit & al., 2012a). The tribal classification has either remained unresolved (Kadereit & al., 2003) or has been rejected (Shepherd & al., 2005b;Kadereit & al., 2006;Kapralov & al., 2006). Kadereit & al.…”

A new species ofArthrocnemum(Salicornioideae: Chenopodiaceae-Amaranthaceae) from West Africa, with a revised characterization of the genus

“…10.1]), and none of the species recognized by MoquinTandon (1840) is appropriate for the typification. This and Salicornia including paraphyletic Sarcocornia (Shepherd, Macfarlane and Waycott 2005b;Steffen et al 2015) are overlapping (Zare and Keshavarzi 2007). Despite many morphological homologies (shrubby life history; glabrous stem; opposite scale-like leaves and bracts; cymes consisting of three flowers; rupture of the lower part of both perianth and pericarp making the ripe seed free; vertical embryo position) and similar (saline) habitats, there are several important traits unambiguously distinguishing Arthrocnemum from the Salicornia/Sarcocornia group (Table 1; see also De Fraine 1913;Ferguson 1964;Sukhorukov 2014).…”

“…Shepherd, Waycott and Calladine, 2004;Kadereit, Mucina and Freitag, 2006;Kadereit and Yaprak 2008) and carpological (Sukhorukov 2014) results show that Arthrocnemum is closely related to the monotypic genus Microcnemum found in the Mediterranean region. The genera are nested within one clade (Shepherd, Macfarlane and Waycott, 2005b;Kadereit, Mucina and Freitag, 2006;Kadereit and Yaprak 2008), which is clearly distant from both Salicornia and Sarcocornia, which together form a separate lineage. Carpologically both Arthrocnemum and Microcnemum possess black seeds with a thick, crustaceous coat often forming stout (papilla-like) outgrowths from the testa cells, and with "stalactites" on the outer cell walls of the testa (Sukhorukov 2014).…”

Pollen morphology of some species of Amaranthaceae s. lat. common in Italy

“…(Alkhani & al. 2003;Iamonico 2009;McAndrews & Swanson 1967;Pinar & Inceoglu 1999;Riollet & Bonnefille 1976;Shepherd & al. 2005;Soliman 2006;Toderich & al.…”