Evidence for species differentiation within the Ancistrocladus tectorius complex (Ancistrocladaceae) in Southeast Asia: a molecular approach

Microsatellites facilitate species delimitation in Congolese Ancistrocladus (Ancistrocladaceae), a genus with pharmacologically potent naphthylisoquinoline alkaloids

“…They were included in order to investigate the species assignment of genotype clusters generated by the statistical analysis of the Congolese material. Genomic DNA for all samples was extracted from silica-dried material, as described by Meimberg & al. (2010).…”

“…However, the current species limits within Ancistrocladus seem to be inadequate and the number of recognized species is certainly underestimated. A recent molecular survey, using nuclear and chloroplast DNA sequences as well as DNA fingerprints, strongly indicated that the number of species in Thailand and Malaysia is higher than expected (Meimberg & al., 2010). This could explain why samples of certain species have greatly differing alkaloid patterns depending on the source of the material (e.g., Manfredi & al., 1996;Nguyen & al., 1997; (Pellegrin, 1951), with its occurrence in the Congo area recorded later on (Taylor & al., 2005).…”

“…Classic nuclear markers, like ITS, have only had limited success in discriminating between these taxa. Meimberg & al. (2010) identified two ribotypes in the Congolese species; ribotype IC2 was the most common one, restricted to A. ealaensis, A. letestui, and several samples of A. congolensis, while ribotype IC1 was detected in A. likoko.…”

Evolution of Asparagus L. (Asparagaceae): Out-of-South-Africa and multiple origins of sexual dimorphism

“…In some cases, such as the genus Kniphofia, all tested species have been shown to be paraphyletic (Ramdhani et al, 2009). The potential explanations for the occurrence of paraphyletic species have attracted much attention (Meimberg et al, 2010;Ramdhani et al, 2009;Rieseberg and Brouillet, 1994). A simple approach is to argue that only monophyletic species should be recognized (Baum and Donoghue, 1995;Mishler and Theriot, 2000), or that the concepts of mono-or paraphyly do not apply to species (Davis and Nixon, 1992).…”

“…Two mechanisms are commonly proposed: post-speciation gene flow (e.g., hybridization) and/or lineage sorting (Meimberg et al, 2010;Ramdhani et al, 2009). There is evidence of polyploidy in Asparagus (Jessop, 1966), and although hybrids can be made between some closely related species in the genus, there appear to be sterility barriers among many species (Falavigna et al, 2008;Ito et al, 2008).…”