David E. Symon

University of Helsinki, Helsinki, Province of Southern Finland, Finland

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Publications (2)3.82 Total impact

  • Source
    Péter Poczai, Jaakko Hyvönen, David E Symon
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    ABSTRACT: Kangaroo apples, subgenus Archaesolanum, are a unique and still poorly known group within the genus Solanum. Here we aimed to reveal phylogeny, historical biogeography and age of diversification of Archaesolanum. We sampled all recognized species of the group and sequenced three chloroplast regions, the trnT-trnL spacer, trnL intron and trnL-trnF spacer to calibrate a molecular clock to estimate the age of the group. Distributional data were combined with the results of phylogenetic analysis to track the historical processes responsible for the current range of the group. Our analysis supported the monophyly of the kangaroo apples and the biogeographical disjunction between the two subclades within the group. Based on the divergence time estimates the most recent common ancestor of kangaroo apples is from the late Miocene age (~9 MYA). Based on the age estimate the common ancestors of the kangaroo apples are presumed to have arrived in Australia by long-distance dispersal. The two distinct lineages within the group have separated during the aridification of the continent and further speciated in the brief resurgence of rainforests during the Pliocene.
    Molecular Biology Reports 11/2011; 38(8):5243-59. · 2.51 Impact Factor
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    ABSTRACT: The subgenus Archaesolanum is a group composed of eight species with a characteristic chromosome number based on n=x=23 and an area restricted to the South Pacific. This subgenus is an isolated group of Solanum for which extensive information about phylogenetic relationships based on molecular genetic methods is lacking. This study represents an approach to analyze genetic relationships within this group. In this context, seven species were examined using random amplified polymorphic DNA (RAPD) markers. In further analysis, the amplification products of two chloroplast regions (trnS-trnG and rbcL) were studied with polymerase chain reaction (PCR) restriction fragment length polymorphism (RFLP) method. Screening for the presence of unique mitochondrial rearrangements was also carried out using universal mitochondrial primers for the detection of fragment length polymorphisms. We identified two major groups within the subgenus; one was composed of the members of ser. Avicularia and Laciniata, while the other was formed by species belonging to ser. Similia. It is suggested that the taxonomic status of series within the Archaesolanum clade should be revised. The hybrid origin of S.laciniatum was also tested, and two hypotheses regarding its phylogeny are assumed. KeywordsArchaesolanum–Phylogenetic relationships– Solanum –PCR-RFLP–RAPD–Kangaroo apples
    Plant Systematics and Evolution 01/2010; 291(1):35-47. · 1.31 Impact Factor

Publication Stats

5 Citations
3.82 Total Impact Points


  • 2011
    • University of Helsinki
      • Plant Biology
      Helsinki, Province of Southern Finland, Finland