Molecular phylogenetics, seed morphometrics, chromosome number evolution and systematics of EuropeanElatineL. (Elatinaceae) species

Abstract

The genus Elatine contains ca 25 species, all of which are small, herbaceous annuals distributed in ephemeral waters on both hemispheres. However, due to a high degree of morphological variability (as a consequence of their amphibious life-style), the taxonomy of this genus remains controversial. Thus, to fill this gap in knowledge, we present a detailed molecular phylogenetic study of this genus based on nuclear (rITS) and plastid (accD-psaI, psbJ-petA, ycf6-psbM-trnD) sequences using 27 samples from 13 species. On the basis of this phylogenetic analysis, we provide a solid phylogenetic background for the modern taxonomy of the European members of the genus. Traditionally accepted sections of this tree (i.e., Crypta and Elatinella) were found to be monophyletic; only E. borchoni—found to be a basal member of the genus—has to be excluded from the latter lineage to achieve monophyly. A number of taxonomic conclusions can also be drawn: E. hexandra, a high-ploid species, is most likely a stabilised hybrid between the main sections; E. campylosperma merits full species status based on both molecular and morphological evidence; E. gussonei is a more widespread and genetically diverse species with two main lineages; and the presence of the Asian E. ambigua in the European flora is questionable. The main lineages recovered in this analysis are also supported by a number of synapomorphic morphological characters as well as uniform chromosome counts. Based on all the evidence presented here, two new subsections within Elatinella are described: subsection Hydropipera consisting of the temperate species of the section, and subsection Macropodae including the Mediterranean species of the section.

Seed mass, hardness, and phylogeny explain the potential for endozoochory by granivorous waterbirds

“…Field tissue samples were stored in silica gel prior to extraction (Chase & Hills, 1991). A modified CTAB extraction protocol was used to obtain DNA extracts, as detailed in Sramkó et al (2016). Universal primer ITS4 (White, Bruns, Lee, & Taylor, 1990) and angiosperm-specific primer ITS1A described by Gulyás et al.…”

“…Universal primer ITS4 (White, Bruns, Lee, & Taylor, 1990) and angiosperm-specific primer ITS1A described by Gulyás et al. (2005) were used to amplify the target DNA region using the PCR conditions as described in Sramkó et al (2016). Specific amplicons were submitted to a commercial sequencing service provided by Macrogen Inc. (Korea).…”

Seed morphometric characteristics of European species of Elatine (Elatinaceae)

“…Recently, Elatine species have been of interest to researchers because of their rarity throughout their range, relatively poorly known distribution and taxonomy, ecology, karyology and phylogenetic relationships (e.g.,  Popiela, 2005; Misfud, 2006; Uotila, 2009a; Uotila, 2010; Popiela & Łysko, 2010; Popiela & Łysko, 2011; Popiela et al, 2011; Popiela et al, 2012; Popiela, Łysko & Molnár, 2013; Popiela et al, 2015; Takács, 2013; Molnár et al, 2013; Molnár, Popiela & Lukács, 2013; Šumberova & Hrivnak, 2013; Kalinka et al, 2014; Kalinka et al, 2015; Cai et al, 2016; Sramkó et al, 2016). The above-mentioned authors emphasized that the erratic temporal appearance of Elatine species depends mainly on environmental factors; for example, plants develop as aquatic or terrestrial forms, and, moreover, they are morphologically variable depending on the phase of drying on the ground.…”

The rare aquatic angiosperm Elatine gussonei (Elatinaceae) is more widely distributed than previously thought

“…Samples from Sicily, Morocco and Spain form a monophyletic group, whereas samples from Lampedusa and Malta are clustered together with E. macropoda Guss. due to recent hybridisation between the two species (Sramkó et al, 2016). Unfortunately, Sramkó et al (2016) failed to point out this hybrid lineage E. gussonei × macropoda in their paper.…”

“…Here, we report new records of E. gussonei around the Mediterranean region which indicate a major extension of the previously recognized distribution. According to our recently published molecular phylogeny (Sramkó et al, 2016), E. gussonei is clearly a separate species. Samples from Sicily, Morocco and Spain form a monophyletic group, whereas samples from Lampedusa and Malta are clustered together with E. macropoda Guss.…”