An evaluation of the taxonomic distinctness of two Geonoma macrostachys (Arecaceae) varieties based on intersimple sequence repeat (ISSR) variation
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Roncal, J., J. Francisco-Ortega, and C. E. Lewis. 2007. An evaluation of the taxonomic distinctness of two Geonoma macrostachys (Arecaceae) varieties based on intersimple sequence repeat (ISSR) variation. Botanical Journal of the Linnean Society 153:381–392.
Abstract:
The latest taxonomic account for the palms of the Amazon recognizes two common and widespread varieties of Geonoma macrostachys (Arecaceae) in western Amazonia: acaulis and macrostachys . These varieties are joined by intermediates, which obscure their taxonomic boundaries. An evaluation of the genetic distinctness between G. macrostachys varieties at a local and regional scale is presented. Thirty-one G. macrostachys individuals were randomly sampled from four Peruvian tropical moist forests. Twenty-seven intersimple sequence repeat (ISSR) primers were used, and all clear and reproducible bands were scored and analysed. Of the 99 ISSR bands produced, 51.52% were polymorphic. Nei’s gene diversity value (H) was 0.2274 and Shannon’s information index (I) was 0.3237. Clustering, ordination, and analyses of molecular variance (AMOVAs) suggested a lack of genetic distinctness between varieties at the regional level. Individuals clustered by geographical provenance, and two main groups were identified. A significant genetic differentiation between sympatric varieties occurred only in the northern locality (ΦST = 0.359, P = 0.000). A hierarchical AMOVA revealed that the genetic diversity in G. macrostachys mainly lies between localities (76.58%). Mantel’s test revealed no significant correlation between the geographical and genetic distances between individuals. We do not support the recognition of the two taxonomic varieties studied.
Keywords: analysis of molecular variance (AMOVA); genetic distinctness; palms; Peru; species complex