An evaluation of the taxonomic distinctness of two Geonoma macrostachys (Arecaceae) varieties based on intersimple sequence repeat (ISSR) variation

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 ( Φ ST = 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.

Diversidade genética de Copernicia prunifera com o uso de marcadores moleculares ISSR

“…Tomando por base essa definição, podemos observar que a população estudada possui diversidade genética intermediária. Roncal et al (2006) estudando a variabilidade genética de uma população de Geonoma macrostachys Mart. (Arecaeae), por meio de marcadores ISSR, encontraram valores inferiores para diversidade de Nei (0,227) e para o índice de Shannon (0,323), quando comparados com os valores encontrados no presente trabalho.…”

Disturbance and Resilience in Tropical American Palm Populations and Communities

“…Additionally, evidence of high allelic variation at SSR loci (short sequence repeat) has been found for Attalea phalerata (Choo et al, 2010), Acrocomia aculeata (Nucci et al, 2008) and Oenocarpus bacaba (Lepsch-Cunha et al, 2003). Exceptions to the pattern of high diversity were reported by McClenaghan & Beauchamp (1986) and Roncal et al (2007). The former research suggested a low allozymic variation in the long-lived Washingtonia filifera that was associated with recent colonization events.…”

An evaluation of the species boundaries of two putative taxonomic entities of Euterpe (Arecaceae) based on reproductive and morphological features

“…In this context, estimates of the number of species of palms vary greatly depending on the point of view of the researcher, and some of the past debate over the recognition of palm species has been caused by the paucity and poor quality of available herbarium specimens, which frequently lack informative characters that permit positive identification (Henderson, 1999(Henderson, , 2004Henderson et al, 2008;Roncal et al, 2007). Henderson and Galeano (1996) addressed the status of E. espiritosantensis based on observations from available herbarium specimens, and in their opinion specimens of putative E. espiritosantensis were insufficiently distinct from those of E. edulis to justify recognition of the former.…”

“…Hybrid development does not mean that the taxa involved are only one species (Coyne and Orr, 2004). Disagreements over whether local forms should be classified as species, infraspecific taxa or results of natural intraspecific variation have led to varying estimates of species numbers in the palm family (Henderson, 2004;Henderson and Martins, 2002;Roncal et al, 2007). One example of such a taxonomic controversy involves the Euterpe genus.…”