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Geographic diversity cline of R gene homologs in wild populations of Solanum pimpinellifolium (Solanaceae)
Author(s) -
Caicedo Ana L.
Publication year - 2008
Publication title -
american journal of botany
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.218
H-Index - 151
eISSN - 1537-2197
pISSN - 0002-9122
DOI - 10.3732/ajb.95.3.393
Subject(s) - cline (biology) , biology , outcrossing , balancing selection , natural selection , population , genetics , evolutionary biology , genetic diversity , gene , selection (genetic algorithm) , allele , ecology , demography , pollen , sociology , artificial intelligence , computer science
Plant resistance ( R ) genes tend to be highly variable within plant species and are thought to be under natural selection; however, little is known about the geographic distribution of R gene diversity within and among plant populations. To determine the possible roles of demography and selection on R gene evolution, patterns of diversity at the multigenic Cf‐2 R gene family were studied in Solanum pimpinellifolium populations along the northern coast of Peru. Population diversity levels of Cf‐2 homologs follow a latitudinal cline, consistent with the species's history of gradual colonization of the Peruvian coast and population variation in outcrossing levels. Although previous evidence suggests that selection has shaped the DNA sequence content of the Cf‐2 genes, current results imply that the geographic distribution of Cf‐2 homolog diversity has been shaped primarily by demographic factors or by selective pressures with a clinal distribution.