Occurrence and evolutionary origins of polyploids in the clubmoss 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. Also reported for the first time are data confirming that D. multispicatum and D. veitchii, representing the putative parent lineages of D. wightianum, are diploids. Phylogenetic analyses of the nuclear regions RPB2, LEAFY and LAMB4 reveal that putative tetraploid accessions are of allopolyploid origin. Diphasiastrum zanclophyllum shows close relationship to the North American taxon D. digitatum on the maternal side, but the paternal relationship is less clear. Two accessions from Asia, both inferred to be polyploid, have D. veitchii as the maternal parent, whereas the paternal paralogs show relationships to D. multispicatum and D. tristachyum, respectively. None of these parental combinations have previously been hypothesized.
Aagaard
S M D
SM
Department of Systematic Biology, Evolutionary Biology Centre, Uppsala University, Norbyv 18D, SE-75236 Uppsala, Sweden. sunniva.aagaard@ebc.uu.se
Greilhuber
Johann
J
Zhang
Xian-Chun
XC
Wikström
Niklas
N
D002467:Cell Nucleus / Q000235:genetics; D018742:DNA, Chloroplast / Q000235:genetics; D018744:DNA, Plant / Q000235:genetics; D019143:Evolution, Molecular; D014644:Genetic Variation; D018745:Genome, Plant; D006239:Haplotypes; D029542:Lycopodiaceae / Q000145:classification / Q000235:genetics*; D018895:Microsatellite Repeats; D010802:Phylogeny; D011123:Polyploidy; D017422:Sequence Analysis, DNA; D013045:Species Specificity
D018742:DNA, Chloroplast; D018744:DNA, Plant