BOB HIRSHON (host):
A transgenic crop thousands of years old. I’m Bob Hirshon and this is Science Update.
The sweet potato may be the world’s oldest transgenic crop, improved by the addition of genes from an entirely different species. But people didn’t genetically engineer it; Mother Nature did. Plant biologist Jan Kreuze at the International Potato Center in Lima, Peru and his colleagues found that every sweet potato carries genes from a kind of soil bacterium—genes not found in the sweet potato’s wild relatives. Kreuze suspects the foreign genes bloat the plant’s roots.
JAN KREUZE (International Potato Center):
We suspect it has something to do with root formation, because that’s what differs sweet potato from its wild relatives is that it makes these nice, delicious tuberous roots.
He suspects that thousands of years ago, people noticed the strange plants with the bulging roots and began cultivating them. The report appears in the Proceedings of the National Academy of Sciences. I’m Bob Hirshon, for AAAS, the science society.