Be the first to like this
Solanum sect. Petota is economically an important group that includes the “cultivated” potato. Wild potatoes are found from the southwestern United States to Chile (RegiónV) y Argentina (Mendoza y La Pampa), from sea level to 4500 m.s.m. This investigation was carried out in order to establish the real number of species growing in Argentina, with the following objectives: 1) To elucidate the taxonomy and distribution of the taxa inhabiting in this country. 2) To analyze the variation patterns of different types of characters (morphological, anatomical, palynological, carpological, seminal), recognizing potential discontinuities. 3) To understand and evaluate the impact of the anatomical vegetative characters and the androecium, pollen, fruit and seed in the systematics of this group. Herbarium specimens from different national and foreign institutions were analyzed for exomorphological studies. It was completed with information obtained from field trips. Microtomic sections of stems, leaves, flowers and fruits were made and stained with Astral Blue-Basic Fuchsin. For palynological studies, standard techniques were followed to observe under light and scanning electronic microscope. Foliar histology, aerial stems (primary and secondary structure), androecium, gynoecium, fruits and seeds and pollen morphology are very homogeneous in the studied species. Solanum infundibuliforme is differentiated by fibres in hypodermis of mesocarp of ripe fruit. Anatomical results provided valuable data for better understanding of this section. Pollen size variations were founded due to altitude and ploidy levels. For the taxonomic treatment, botanical excursions were made in Argentina and neighbouring countries that allowed studying variability of populations, phenology and habitat in which species grow. Maps of travels during 2001-2009 were illustrated. Collection sites and distribution of collected species were mapped with geographical coordinate data using DIVA-GIS software. Herbarium specimens were deposited at CORD, which increased the collection of this group in a 150% with a representation of the totality of the studied species. The taxonomic treatment was developed for this section, 17 species, four hybrids and one subspecies were recognized from Argentina, Synonymies and 17 lectotypes were designated, and 5 superfluous lectotypes were identified. Solanum okadae was excluded and three taxa were recognized as doubtful names. Keys to distinguish groups and species were provided as well as illustrations of some species.