Occurrence and evolutionary origins of polyploids in the club moss genus Diphasiastrum (Lycopodiaceae)

• Two polyploid taxa are commonly recognized in the genus Diphasiastrum, D. wightianum from Asia and D. zanclophyllum from South Africa and Madagascar. Here we present results from Feulgen DNA image densitometry analyses providing the first evidence for the polyploid origin of D. zanclophyllum. Reported for the first time is also data confirming that D. multispicatum and D. veitchii, representing putative parent lineages for D. wightianum, are diploids. Phylogenetic analyses of nuclear regions RPB2, LEAFY and LAMB4 reveal that putative tetraploid accessions are of allopolyploid origin. Diphasiastrum zanclophyllum shows close relationships to the North American taxon D. digitatum on the maternal side, but the paternal relationship is less clear. Two accessions from Asia, both found to be polyploid, have D. veitchii as maternal parent, whereas the paternal paralogs show relationships to D. multispicatum and D. tristachyum, respectively. None of these parental combinations have previously been hypothesized.

Ämnesord

NATURVETENSKAP  -- Biologi (hsv//swe)

NATURAL SCIENCES  -- Biological Sciences (hsv//eng)

Nyckelord

Diphasiastrum

Feulgen DNA image densitometry

Lycopodium

Lycopodiaceae

low-copy nuclear genes

phylogenies

polyploidy

Biology

Biologi

Systematisk botanik

Systematic Botany

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