Solanum pennellii
Northern Peru (Piura) to northern Chile (Tarapaca) in dry rocky hillsides and sandy areas from sea level to 3000 m.
Solanum pennellii is a member of the Potato clade (sensu Weese & Bohs, 2007); within the tomatoes and wild relatives it is the sole member of the “Neolycopersicon group” and is a member of section Lycopersicon.
D’Arcy, W.G. 1972. Solanaceae studies II: typification of subdivisions of Solanum.
Ann. Missouri Bot. Gard. 59: 262-278.
Eshed, Y., G. Gera, & D. Zamir 1996. A genome-wide search for wild-species alleles that increase horticultural yield of processing tomatoes.
Theor. Appl. Genet. 93: 877-886.
Holtan, H.E.E. & S. Hake 2003. Quantitative trait analysis of leaf dissection in tomato using Lycopersicon pennelli segmented introgression lines.
Genetics 165:1541-1550.
Carrizo García, C. 2003. Morfología comparada del androceo en tomates y especies afines (Solaneae, Solanaceae).
Kurtziana 30: 27-39.
Glover, B.J., S. Bunnewell, & C. Martin 2004. Convergent evolution with the genus Solanum: the specialized anther cone develops through alternative pathways.
Gene 331: 1-7.
Fridman, E., F. Carrari, Y.-S. Liu, A.R. Fernie, & D. Zamir. 2004. Zooming in on a quantitative trait for tomato yield using interspecific introgressions.
Science 305: 1786-1789.
Solanum pennellii, with its compound leaves with almost orbicular leaflets and anther cones (tubes) with lateral hairs connecting the anthers but without a sterile apical appendage, is easy to distinguish from all other tomato relatives. Carrizo García (2003) recognized S. pennellii in the genus Solanum, and the other species of sect. Lycopersicon in the genus Lycopersicon due to this anther difference. In contrast, D'Arcy (1972) placed S. pennellii in Lycopersicon. The spathulate calyx lobes and slightly zygomorphic flowers are also unique (in the tomatoes) in S. pennellii. Despite these distinctive characteristics, specimens of S. pennellii can be confused with S. corneliomulleri, especially when sterile or in fruit. Solanum pennellii never has the long glandular trichomes characteristic of S. corneliomulleri, but instead has shorter, stickier pubescence. Pubescence morphs in S. pennellii have been described as subspecific taxa, but the differences are not consistent either geographically or in terms of habitat, suggesting the trait is of little taxonomic importance. Interestingly, in more pubescent individuals of S. pennellii, this increase in pubescence extends to the anthers (interlocking papillae) and may be of interest in further investigations of anther morphology in the groups (see Glover et al. 2004).
Solanum pennellii is an important component of the lomas vegetation of the west coast of South America in the desert regions, but also occurs in dry valleys along the western Andean slope. Blooming times of populations in the lomas and in other habitats appear to differ, with lomas populations blooming in September to November, coinciding with the foggy season on the Peruvian coast.
One TGRC accession of S. pennellii (LA716) from near Atico in the Department of Arequipa in southern Peru (vouchered by Correll & Smith P-173) has been of importance in the development segmented introgression lines with the S. lycopersicum cultivar M82 (see Eshed & Zamir 1994, 1995, http://zamir.sgn.cornell.edu/Qtl/il_story.htm). Each of the 76 IL lines contains a single introgressed segment of the S. pennellii genome giving complete coverage of the genome. This resource has been critical to the understanding of yield parameters (Eshed et al. 1996; Fridman et al. 2004) and leaf dissection (Holtan & Hake 2003).
The type specimen of var. elachistus (Hoffman 89-13, CONC) is the only Chilean collection we have seen, but this species certainly occurs in more locations in Chile.