Submitted to: Taxon
Publication Type: Peer reviewed journal
Publication Acceptance Date: 2/15/2003
Publication Date: 5/13/2005
Citation: Spooner, D.M., Peralta, I., Knapp, S. 2005. Comparison of AFLPs with other markers for phylogenetic inference in wild tomatoes (Solanum L. section Lycopersicon [Mill.] Wettst. Taxon. 54:43-61. Interpretive Summary: Wild tomatoes represent one of the world's most important food crops relative to dollar value and worldwide nutrition. The latest taxonomic treatment of wild tomatoes recognized nine wild species, native to western South America. All of these have proven and/or potential use as breeding stock to improve the cultivated tomato crop. Taxonomy represents a way to investigate the number of species and their inter-relationships, and to classify this diversity, in a way useful to breeders and genebank managers. Different classifications of tomato, however, are based on different criteria (how the species can intercross with each other or how they appear outwardly), creating confusion about the most appropriate taxonomy to use. This study uses a molecular marker, technically referred to as AFLPs, to further investigate the number of species of wild tomato, and to understand how these species are interrelated. It is a companion study to two other studies by the first two authors using the outward form of the plant (morphology), and another molecular marker technically called GBSSI or waxy. The AFLP results are largely in agreement with these latter two studies and show that the classification based on how they can intercross is likely not a good one, and also suggests the need to recognize another wild tomato species.
Technical Abstract: Wild tomatoes (Solanum L. section Lycopersicon [Mill.] Wettst. subsection Lycopersicon) are native to western South America. Different classifications have been based on morphological or biological species concepts. Molecular data from mitochondrial, nuclear, and chloroplast DNA restriction length fragment polymorphisms, internal transcribed spacers of nuclear ribosomal DNA (ITS), nuclear microsatellites, isozymes, and most recently gene sequences of the single-copy nuclear encoded Granule-bound Starch Synthase gene (GBSSI or waxy) and morphology, also have been used to examine hypotheses of species relationships. This study is a companion study to the waxy gene sequence study and morphological study of relationships of all nine wild tomato species, with a concentration on the most widespread and variable species S. peruvianum. These new AFLP data largely are concordant with the waxy and morphological data and support the nine species outlined by the latest treatment by C. Rick, but demonstrate the distinct nature of the northern and southern Peruvian populations of S. peruvianum, and suggest that they may represent distinct species.