Domestication of Capsicum annuum chile pepper provides insights into crop origin and evolution

Jun 19, 2009
These are varieties of four domesticated chiles. Credit: The Chile Pepper Institute, New Mexico State University, Las Cruces, New Mexico.

Without the process of domestication, humans would still be hunters and gatherers, and modern civilization would look very different. Fortunately, for all of us who do not relish the thought of spending our days searching for nuts and berries, early civilizations successfully cultivated many species of animals and plants found in their surroundings. Current studies of the domestication of various species provide a fascinating glimpse into the past.

A recent article by Dr. Seung-Chul Kim and colleagues in the June 2009 issue of the American Journal of Botany explores the of chiles. These hot peppers, found in everything from hot chocolate to salsa, have long played an important role in the diets of Mesoamerican people, possibly since as early as ~8000 B.C. Capsicum annuum is one of five domesticated species of chiles and is notable as one of the primary components, along with maize, of the diet of Mesoamerican peoples. However, little has been known regarding the original location of domestication of C. annuum, the number of times it was domesticated, and the genetic diversity present in wild relatives.

To answer these questions, Dr. Kim and his team examined DNA sequence variation and patterns at three nuclear loci in a broad selection of semiwild and domesticated individuals. Dr. Kim et al. found a large amount of diversity in individuals from the Yucatan Peninsula, making this a center of diversity for chiles and possibly a location of C. annuum domestication. Previously, the eastern part of central had been considered to be the primary center of domestication of C. annuum. On the basis of patterns in the sequence data, Dr. Kim et al. hypothesize that chiles were independently domesticated several times from geographically distant wild progenitors by different prehistoric cultures in Mexico, in contrast to maize and beans which appear to have been domesticated only once.

Geographical separation among cultivated populations was reflected in DNA sequence variation. This separation suggests that seed exchange among farmers from distant locations is not significantly influencing genetic diversity, in contrast to maize and beans seeds, which are traded by farmers across long distances. Less genetic diversification was seen in wild populations of C. annuum from distant locales, perhaps as a result of long-distance seed dispersal by birds and mammals.

Across the three loci studied, Dr. Kim and colleagues found an average reduction in diversity of 10% in domesticated individuals compared with the semiwild individuals. Domesticated chiles in traditional agricultural habits, however, harbor unique gene pools and serve as important reservoirs of important for conserving biodiversity.

More information: American Journal of Botany -- www.amjbot.org

Source: American Journal of Botany

Explore further: Male monkey filmed caring for dying mate (w/ Video)

add to favorites email to friend print save as pdf

Related Stories

Rice domestiction confiirmed genetically

Sep 08, 2006

Biologists from Washington University in St. Louis and their collaborators from Taiwan have examined the DNA sequence family tree of rice varieties and have determined that the crop was domesticated independently ...

Corn's roots dig deeper into South America

Mar 24, 2008

Corn has long been known as the primary food crop in prehistoric North and Central America. Now it appears it may have been an important part of the South American diet for much longer than previously thought, according to ...

Wild about the evolution of domesticated yeast

Feb 12, 2009

(PhysOrg.com) -- It lives all around us and is probably one of the earliest domesticated organisms. Humans have been using it for tens of thousands of years. There is evidence that the Ancient Egyptians used it for baking ...

Getting to the Roots of Sunflower Cultivation

May 22, 2008

Global warming could affect one of the world's major oil seed crops, the sunflower. Drawing on genetic information from early plant stocks is key to improving future harvests.

Ancient Mexican maize varieties

Jun 26, 2008

Maize was first domesticated in the highlands of Mexico about 10,000 years ago and is now one of the most important crop plants in the world. It is a member of the grass family, which also hosts the world's other major ...

Recommended for you

Male monkey filmed caring for dying mate (w/ Video)

Apr 18, 2014

(Phys.org) —The incident was captured by Dr Bruna Bezerra and colleagues in the Atlantic Forest in the Northeast of Brazil.  Dr Bezerra is a Research Associate at the University of Bristol and a Professor ...

Orchid named after UC Riverside researcher

Apr 17, 2014

One day about eight years ago, Katia Silvera, a postdoctoral scholar at the University of California, Riverside, and her father were on a field trip in a mountainous area in central Panama when they stumbled ...

In sex-reversed cave insects, females have the penises

Apr 17, 2014

Researchers reporting in the Cell Press journal Current Biology on April 17 have discovered little-known cave insects with rather novel sex lives. The Brazilian insects, which represent four distinct but re ...

Fear of the cuckoo mafia

Apr 17, 2014

If a restaurant owner fails to pay the protection money demanded of him, he can expect his premises to be trashed. Warnings like these are seldom required, however, as fear of the consequences is enough to ...

User comments : 0

More news stories

Cancer stem cells linked to drug resistance

Most drugs used to treat lung, breast and pancreatic cancers also promote drug-resistance and ultimately spur tumor growth. Researchers at the University of California, San Diego School of Medicine have discovered ...