In prehistoric times farmers across the world domesticated wild plants to create an agricultural revolution. As a result the ancestral plants have been lost, causing problems for anyone studying the domestication process of modern-day varieties, but that might change. A team led by Fabiola Parra at the Universidad Nacional Autnoma de Mxico (UNAM) has managed to trace a domesticated cactus, the Gray Ghost Organ Pipe (Stenocereus pruinosus) to its living ancestor that can still be found in the Tehuacn Valley in Mexico. The research is published in the September 2010 edition of the Annals of Botany at http://aob.oxfordjournals.org/cgi/content/abstract/106/3/483
Cacti were domesticated in prehistoric times for their fruit, pitaya. They're eaten around the world, but it's the pitaya of the Gray Ghost Organ Pipe that are most prized for their quality. Parra's team went to the Tehuacn valley to examine the cacti and how they grew both in gardens and forests managed by the local people and in the wild.
Dr. Alejandro Casas, an ethnobotanist on the project, said: "What we found is that the people of the Tehuacn Valley are carefully selecting and cultivating cacti to produce the pitaya they want. They're not attempting to produce one type of pitayo. They have a rich understanding of the cacti and are able to produce fruits with a variety of colours and tastes."
Genetic analysis revealed the garden cacti were more likely to carry duplicate copies of alleles (gene variants) in their chromosomes than their wild counterparts. It shows that evidence of artificial selection has left its mark in the cactus DNA. However, the genes from cacti grown using traditional methods in managed forests showed that domestication is not a simple process.
Casas added: "We found that the forest cacti showed more diversity in their genes than expected. It is not a case of finding
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