SYSTEMATICS, GENETIC DIVERSITY ASSESSMENT, AND ACQUISITION OF POTATOES, CARROTS, AND THEIR RELATED WILD RELATIVES
Location: Vegetable Crops Research Unit
Title: Species Boundaries and Interrelationships of Solanum Series Conicibaccata
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: March 2, 2009
Publication Date: July 15, 2009
Citation: Fajardo, D., Spooner, D.M. 2009. Species Boundaries and Interrelationships of Solanum Series Conicibaccata [abstract]. Botany & Mycology 2009. p. 20.
Solanum series Conicibaccata Bitter previously contained 40 wild potato (sect. Petota Dumort.) species distributed from southern Mexico to central Bolivia. It contained diploids (2n = 2x = 24), tetraploids (2n = 4x= 48) and hexaploids (2n = 6x = 72). We previously reported the morphological phenetics of this group, and here report our final taxonomic decisions based on prior morphological data, plastid DNA restriction site data, AFLPs, herbarium specimens, and five nuclear ortholog (COSII) DNA sequences (concatenated length 5158 bp). The morphological study shows low resolution among the species. While the nuclear orthologs also show low resolution for the species, they clearly show the diploids to be members of “clade 4” species related to cultivated potato, and show allopolyploid origins for the tetraploids and hexaploids from the diploids and members of “clade 3” species containing members of series Piurana Hawkes and other related species. Low bootstrap support values among the species suggest very recent origins. Combined data lead us to recognize only 17 species: S. ayacuchense Ochoa, S. buesii Vargas, S. bombycinum Ochoa, S. burkartii Ochoa, S. colombianum Dunal, S. flahaultii Bitter, S. garcia-barrigae Ochoa, S. laxissimum Bitter, S. limbaniense Ochoa, S. lobbianum Bitter, S. longiconicum Bitter, S. neovavilovii Ochoa, S. nubicola Ochoa, S. oxycarpum Schiede, S. pillahuatense Vargas, S. salasianum Ochoa,and S. violaceimarmoratum Bitter. Other species that were previously considered as members of series Conicibaccata (S. chomatophilum Bitter and S. paucijugum Bitter) now are placed inside an expanded series Piurana. Solanum colombianum is by far the most widely distributed and polymorphic polyploid member of the series, composed of both tetraploid cytotypes (including 12 previously recognized species), and the hexaploid cytotypes S. moscopanum, S. sucubunense and S. tundalomense.