A new global study reveals the extent to which high-yielding rice varieties favored in the decades since the “Green Revolution” have a propensity to go feral, turning a staple food crop into a weedy scourge.
Weedy rice is a de-domesticated form of rice that infests paddies worldwide and aggressively outcompetes cultivated varieties. A new study led by biologists at Washington University in St. Louis shows that weed populations have evolved multiple times from cultivated rice, and a strikingly high proportion of contemporary Asian weed strains can be traced to a few Green Revolution cultivars that were widely grown in the late 20th century.
The scientists believe that a universal process is at work, acting at a genomic and molecular level to allow rapid adaptation to weediness. The new study is published March 26 in the journal Genome Biology.
“One of the hallmarks of the Green Revolution was the use of cross-breeding to create high-yielding cultivars,” said Kenneth M. Olsen, professor of biology in Arts & Sciences. “For rice and many other crops, this involved hybridizing traditional varieties to combine their best traits. This type of rice breeding was very different from traditional rice farming, where varieties aren’t cross-bred and farmers replant seed from their own harvests.”
Read more at Washington University in St. Louis
Image: Biologist Kenneth M. Olsen tends rice in the Jeanette Goldfarb Plant Growth Facility at Washington University in St. Louis. (Credit: Joe Angeles/Washington University)