Interspecific Reproductive Barriers (IRBs) in Wild Tomatoes

The monophyletic clade of about a dozen species of wild tomatoes found in Ecuador, Peru and Chile have varied mating systems; some are completely self-incompatible (SI), some are mostly SI with some self-compatible (SC) populations, some have populations that segregate for SI and SC and still others are completely self-compatible.  There are many examples of sympatry within the wild tomato clade, but no known cases of hybridization in the wild, indicating that reproductive barriers act to isolate these closely related species even in close proximity. We are interested in discovering the molecular basis of these reproductive barriers between the wild tomato species, and have identified both pollen and pistil factors that are involved in post-pollination, prezygotic barriers. In addition, we are seeking to determine the role of these barriers in the evolution of new lineages by studying incipient barriers at species’ margins.