Discovery of a rice gene linked to resistance to Cercospora disease has helped in the development of new rice varieties.
“It’s allowed us to breed for resistance,” said Don Groth, LSU AgCenter plant pathologist.
Groth said it was originally thought that several genes were responsible for Cercospora susceptibility or resistance. He said developing resistance before discovery of the gene was difficult because the disease was not prevalent every year.
With the gene identified, he said, new lines will continue to be tested for resistance.
“Even if the gene is there, you want to make sure it’s functioning,” Groth said.
Christopher Addison found the genetic trait, identified as CRSP2.1, according to Adam Famoso, LSU AgCenter rice breeder. Famoso said Groth scored a breeding population that was segregating for disease.
“It was clear as day there was a very strong gene for Cercospora resistance,” Famoso said.
Then Addison took over the project. His analysis determined that the single gene responsible for Cercospora susceptibility was one of 40 to 50 genes, but current technology does not allow isolation of the lone gene, Famoso said.
The origin of the gene probably can be traced back to a California variety L202 that was used as a parent for Cypress, Famoso said. Cypress was then used as a parent for other popular varieties, including Cocodrie, as well as Clearfield.
Famoso said a line without the gene will not be automatically excluded if it has other desirable traits.
The LSU AgCenter and the LSU College of Agriculture