Domesticated chili pepper originated in Central-east Mexico

Researchers have said that domesticated chili pepper originated in Central-east Mexico.

Results from the four-pronged investigation - based on linguistic and ecological evidence as well as the more traditional archaeological and genetic data - suggest a regional, rather than a geographically specific, birthplace for the domesticated chili pepper. That region, extending from southern Puebla and northern Oaxaca to southeastern Veracruz, is further south than was previously thought, the researchers found.

UC Davis plant scientist Paul Gepts, the study's senior author said identifying the origin of the chili pepper is not just an academic exercise, asserted that by tracing back the ancestry of any domesticated plant, we can better understand the genetic evolution of that species and the origin of agriculture - a major step in human evolution in different regions of the world.

To determine crop origins, scientists have traditionally studied the plants' genetic makeup in geographic areas where they have observed high diversity among the crop's wild ancestors. More recently, they have also examined archaeological remains of plants, including pollen, starch grains and even mineralized plant secretions.

For this chili pepper study, the researchers used these two traditional approaches but also considered historical languages, looking for the earliest linguistic evidence that a cultivated chili pepper existed.

They also developed a model for the distribution of related plant species, to predict the areas most environmentally suitable for the chili pepper and its wild ancestors.

The genetic evidence seemed to point more to northeastern Mexico as the chili pepper's area of domestication; however there was collectively more evidence from all four lines of study supporting the central-east region as the area of origin.

The study findings have been published online in the Proceedings of the National Academy of Sciences.