ARS | Publication request: Biogeographic implications of the striking discovery of a 4000 kilometer disjunct population of the wild potato Solanum morelliforme in South America

Submitted to: Systematic Botany
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 9, 2011
Publication Date: November 30, 2011
Citation: Simon, R., Fuentes, A.F., Spooner, D.M. 2011. Biogeographic implications of the striking discovery of a 4000 kilometer disjunct population of the wild potato Solanum morelliforme in South America. Systematic Botany. 36(4):1062-1067.

Interpretive Summary: The cultivated potato of world commerce has about 100 wild species relatives that are of great value to improve, through plant breeding, disease resistances and quality traits. Hence, there is great effort to collect and study the distributions of the wild potato species that are distributed from the southeastern United States to Uruguay and adjacent central Argentina and south-central Chile. One of these species, technically known as Solanum morelliforme, was previously known only from Mexico and Central America. Recently it was discovered in South America, in Bolivia, representing the first species known from both Mexico and Central America and South America. This study uses a procedure, technically known as maximum entropy analyses, to use the environmental measurements from one set of localities (such as rainfall and temperature) to predict where it may be found in similar localities that have similar sets of environments elsewhere. Maximum entropy analysis predicted with great precision that Solanum morelliforme could be found where occurs in Bolivia, and showed other places in South America (in Bolivia and Peru) where it may be found. This study not only demonstrates the value of this technique, but alerts collectors to look for this species in these new places in South America.

Technical Abstract: Solanum morelliforme is an epiphytic wild potato (Solanum section Petota) species widely distributed throughout central Mexico to Honduras. A strikingly disjunct (4000 km) population was recently discovered in Bolivia, representing the first record of this species in South America. Our maximum entropy analyses of 19 climatic variables predicted the occurrence the South American locality with great precision. It demonstrates the strong predictive quality of this procedure and suggests similar localities where this species may be found along the eastern slopes of the Andes in the Yungas region of southern Peru and Bolivia. The presence of S. morelliforme in South America adds to emerging data from other sources to question long-held hypotheses of the origin of section Petota in North and Central America.