Using DNA collected by immigrant farmers in Southern California, scientists at UC Riverside determined that the genetic diversity of the corn planted in their home gardens of recent immigrants far exceeded that of the strains available at their local supermarket. Southern California turns out to be an ideal location in which to study the combined effect of human and plant migration as the Mexican and Central American immigrants there often seed their gardens with crops they have imported from their home countries.


The study, which began back 2008, compared the immigrant’s home garden corn to five commercially available varieties, including two horticultural strains, two industrial varieties, and one bulk-bin variety purchased from an area supermarket. The results showed that corn in the home gardens contained significantly higher levels of genetic diversity than the commercial varieties. The results urged scientists to broaden their inquiry into the nature and diversity of the immigrant corn and how it might carry valuable characteristic relevant to drought tolerance.

Seeking to identify and propagate global crop diversity is essential work today as corporate-driven policies and programs have encouraged the use of only a few modern cultivars, many of which are now patented. The genetic heritage stewarded by small farmers around the planet will be ost forever when they are forced to abandon their farms and gardens to migrate to urban centers.