Chloroplast DNA evidence for genome differentiation in wild potatoes (Solanum sect. Petota: Solanaceae).
Authors:
Spooner, D.M. Sytsma, K.J. Conti, E. USDA, ARS
Source:
American journal of botany. Oct 1991. v. 78 (10), p. 1354-1366.
NALT Subjects:
Solanum chloroplasts DNA phylogeny genetic variation geographical distribution restriction mapping genomics
Other Subjects:
differentiation ploidy
Issue Date:
Oct-1991
Abstract:
Chloroplast DNA restriction site analysis has been used to test Hawkes's phylogenetic interpretations of the genomic data in Solanum sect. Petota. Hawkes hypothesized a diploid (2n = 24) origin of the tuber-bearing members of this group (subsection Potatoe) in Mexico and Central America (as a B genome) with later migrations and evolution to an A genome in South America, later followed by a return migration of the A genome to Mexico and Central America with A x B hybridizations and polyploidizations to produce ser. Longipedicellata (4x) and Demissa (6x). Our results provide partial support for this hypothesis by demonstrating the paraphyletic and primitive nature of the B genome species group, and the monophyletic and derived nature of all A genome and A x B genome species, including S. verrucosum, a hypothesized A genome progenitor of ser. Demissa. Thus, the Mexican and Central American polyploid species must have obtained their cytoplasm from the A genome. However, our results question the Stellata/Rotata hypothesis of Hawkes and the taxonomic placement of S. chomatophilum in ser. Conicibaccata.
