Has the bacterium that causes fire blight become resistant to product used to control the disease? Study aims to find out

Friday, July 3, 2015

by SUSAN MANN

Agriculture and Agri-Food Canada researchers are planning to study pear and apple tree samples to determine if the bacterium causing a destructive disease in those crops is resistant to a control product farmers use.

The researchers have started to collect pear and apple tree samples and will also be collecting them next year, says Agriculture and Agri-Food Canada researcher scientist Antonet Svircev. “The project goes for three years.”

She is in charge of the project for Ontario, while other scientists across Canada will be collecting samples from other areas and studying them. Svircev is stationed at the federal government’s Vineland Research Station.

Researchers will be studying the samples to see if the bacterium, called erwinia amylovora, that causes fire blight carries a gene making it resistant to streptomycin, a product used to control fire blight in Ontario’s commercial orchards since the 1960s.

“There are certain genes within the bacterium that tell us there may be resistance,” Svircev says. “We’re looking for these certain genes for resistance in the bacterium. But just because we find the gene doesn’t mean that there really is resistance so we have to do tests in the lab. We have to confirm it.”

Fire blight is one of the most destructive apple and pear tree diseases. It kills the shoots of the trees and makes them look like they’ve been scorched by fire. BF