"What we are learning suggests there's a whole lot of diversity out there in wild relatives of crop plants or even in landraces, varieties of plants and animals that are highly adapted to local conditions," Olsen said, "that wasn't tapped during the domestication process."
"These plant populations could provide the diversity for continued breeding that is going to be very important as the world faces climatic change," he said. "This is why it is important we understand the early stages of domestication."
Two possible speed bumps
Many crops are distinguished from their wild ancestors with a suite of traits called the domestication syndrome. This includes seeds that remain attached to the plant for harvesting (a trait called nonshattering), reduced branching and robust growth of the central stem and bigger fruits, seeds or tubers.
Over the past 20 years, researchers have begun to identify the genes that control some of the most important domestication traits, no easy task in the days before rapid sequencing, because they had to start with plant traits and work back to unknown genes.
This work showed that many domestication traits were under the control of single genes. For example the gene teosinte branched1 (tb1) converts highly branched teosinte plants into single stalks of corn.
But the seeming importance of single genes could have been an artifact of the method used to identify domestication genes, which required the researcher to pick "candidate" genes and, perhaps, prematurely narrow the search, overlooking indirect genetic effects.
"Little is known about the underlying genetics of domestication," Olsen said. "We decided to look at
|Contact: Diana Lutz|
Washington University in St. Louis