Discovery of the Northern Hemisphere hybrid Potamogeton ×salicifolius in the Pilbara region of Western Australia

Abstract

e interspeci c hybrid Potamogeton ×salicifolius (= P. lucens × P. perfoliatus), so far known only from several countries of Europe and a few countries of Asia, was discovered in Western Australia. Morphology of the Australian specimens ts the range of variation observed in Eurasian specimens. DNA sequencing con rmed the morphological identi cation as a hybrid P. lucens × P. perfoliatus, and identi ed P. lucens as the maternal parent. is identity is surprising because neither of the parental species are known to occur in Western Australia and P. lucens currently does not even occur in the continent. ree possible explanations for the occurrence of P. ×salicifolius in Western Australia are discussed: its relictual occurrence from a time when both the parental species occurred there, long-distance dispersal of a hybrid seed from Eurasia and the remnant of local cultivation or intentional planting.

Cryptic species of pondweeds (Potamogetonaceae) at an intercontinental scale revealed by molecular phylogenetic analyses

“…The occurrence of two species of Potamogeton on both continents ( P. perfoliatus L. and P. crispus L.) indicates that such dispersal does happen. Furthermore, we recently detected a hybrid in Australia ( P. perfoliatus × P. lucens L.) that was previously only known from Europe and Asia (Kaplan & al., 2019). Its maternal parent ( P. lucens ) does not occur in Australia, and the particular genotype of P. lucens that gave rise to the hybrid corresponded to samples from Japan.…”

Evolutionary history and patterns of geographical variation, fertility, and hybridization in Stuckenia (Potamogetonaceae)

“…All were discovered and described in northern Europe ( Hagström, 1916 ), and most of the known occurrences are in the British Isles, Scandinavia, and northeastern Europe ( Preston, 1995 ; Bobrov, 2007 ). Although many DNA-based studies are available for the closely related genus Potamogeton (e.g., Kaplan and Fehrer, 2007 ; Kaplan and Fehrer, 2009 ; Zalewska-Gałosz et al., 2009 ; Zalewska-Gałosz et al., 2010 ; Kaplan et al., 2011 ; Kaplan and Fehrer, 2013 ; Aykurt et al., 2017 ; Zalewska-Gałosz et al., 2018 ; Iida et al., 2018 ; Kaplan et al., 2019 ), the molecular evidence for hybridization in Stuckenia is rare and available for only a few countries: S. filiformis × S. pectinata was documented from Norway and the United Kingdom ( McMullan et al., 2011 ), S. filiformis × S. vaginata from Denmark and Russia ( McMullan et al., 2011 ), and S. pectinata × S. vaginata from the United Kingdom ( King et al., 2001 ; McMullan et al., 2011 ), Denmark, and Ireland ( McMullan et al., 2011 ). This study provides the first DNA proofs for the hybrid origins and the parentages of S. filiformis × S. pectinata from Sweden, Germany, and the USA, that of S. filiformis × S. vaginata from the Siberian part of Russia, Canada, and the USA, and that of S. pectinata × S. vaginata from Finland, Russia, and the USA.…”

“…If required for readability and to determine the exact position and length of indels, individual samples of the 5S-NTS marker were cloned as described in Fehrer et al (2009) except that vector primers instead of PCR primers were used for re-amplification; several clones were sequenced with the M13 primer to obtain full length reads. Most hybrids in Potamogeton maintain ITS ribotypes of both parents (e.g., Kaplan and Fehrer, 2007;Kaplan et al, 2019); hybrid identification in Stuckenia is therefore based on the same marker. For samples that showed character additivity in direct sequences of the ITS region, in the case of strongly skewed ratios of parental copy types, minor and major sequences were determined by peak subtraction; otherwise, the sample was cloned.…”