Close Encounters

Disentangling domestication and environmental effects on plant-herbivore interactions

How has domestication affected herbivory and anti-herbivore defenses of chaya, a plant crop grown for it's leaves in the Yucatan pensula?

Chaya (Cnidoscolus aconitifolius) is a crop species that was domesticated by the Maya in Mexico. In its domestication centre on the Yucatan peninsula of south-eastern Mexico, domesticated chaya coexists with their wild relatives. Domesticated chaya is commonly grown in home gardens whilst wild chaya grows in nearby disturbed vegetation. Wild chaya are evidently thornier than their cultivated counterparts, a trait that has been selected by growers across several years. Studying chaya in its domestication centre presents an opportunity to understand the effects of plant domestication on plant-herbivore interactions, while controlling for the geographic and evolutionary history of endemic herbivores with crops and their wild progenitors.

Leaves of wild Chaya (Cnidoscolus aconitifolius) with evident herbivory. Note the urticant trichomes on the leaf borders and petioles. Image credit: Solís-Montero et al.

In their new study in AoBP, Solís-Montero et al. assess herbivore diversity and abundance, and direct and indirect anti-herbivore defences of wild and cultivated chaya on the Yucatan Peninsula. They assessed these traits both in the field and in a common garden experiment. They found that under both field and controlled conditions domesticated plants were less well defended and were more frequently attacked by herbivores. They also noted that the experimental environment affected both direct and indirect plant defenses, specifically the number of trichomes was reduced in the garden experiment compared to the field whilst the number of ants on each plant was increased. The authors conclude by stating that future studies with other crop species would help to assess whether the patterns detected in their study with chaya can be generalized.

Researcher highlight

Miguel Angel Munguía-Rosas and Virginia Solis-Montero (Miguel’s PhD Student and first author of the paper in AoBP) at their plant nursery with Cnidoscolus aconitifilous.

Miguel Angel Munguía-Rosas is a plant ecologist born in Mexico City. He earned a PhD in Ecology and Management of Natural Resources at the Institute of Ecology in Xalapa, Mexico in 2008. He then spent a couple of years as a posdoc at the University of Northampton, UK and at the University of Yucatan, Mexico. Since 2011, Miguel has been a full-time researcher at Cinvestav, a leading research centre in Mexico. Miguel’s main interests are plant reproductive biology and plant-animal interactions in the context of human activities. Most of his research has been conducted in tropical forest and tropical agreocosystems, particularly in the cultural and biologically diverse region of the Yucatan Peninsula. Miguel also teaches statistics and is an amateur swimmer and drummer.