Next summer’s release of Canada’s first fusarium resistant wheat variety is welcome news to an industry that has seen fusarium-related losses increasing steadily over the past few years.
However, Rob Graf, the wheat breeder who developed AC Emerson, says it’s too early to tell whether other resistant-rated wheat varieties will soon be developed.
Wheat breeders are working on it, but identifying the sources of fusarium head blight resistance and transferring it into new lines is a difficult, time consuming process.
“We’re certainly working on it, as are others, and we do have some material in the pipeline that looks promising, but I would say it’s still a bit early.”
Graf said the source of AC Emerson’s fusarium resistance is not fully understood.
Neither of AC Emerson’s parent lines — CDC Osprey or McClintock — has a resistant rating for fusarium.
CDC Osprey’s resistance is at best intermediate, while McClintock is susceptible.
“The source of resistance in Emerson is a little bit of a mystery,” Graf said.
“We were fortunate to find a segregate that actually showed good resistance. Obviously, we’ve been able to bring together a number of minor genes that somehow work together to give us resistance.”
Graf’s research team has recently started a project aimed at mapping the source of Emerson’s resistance on a molecular level. If the project is successful, the task of developing new fusarium resistant varieties will become far less onerous.
“We will be trying to map this resistance from a molecular standpoint to make it easier to transfer this resistance into future varieties,” he said.
Identifying the source of resistance is similar to looking for a needle in a haystack.
“Fusarium head blight resistance breeding is very difficult,” Graf said.
“It’s not an easy disease to tackle.”