Plant breeders cannot offer a septoria resistance solution – at least not yet
Plant breeders cannot currently offer cereal growers a ‘silver bullet’ when it comes to overcoming the challenge of septoria resistance in cereal crops, according to Nicholas Bird from KWS.
He was speaking at today’s Teagasc Septoria Conference in Dunboyne Castle, Co. Meath.
“The best we can offer is partial septoria resistance, the level of which depends on the parent plants used in a specific breeding programme. But nature tends to level matters off.
Putting a focus on septoria resistance at one level may have a negative impact on traits such as yield potential.
Bird said that septoria is one of 50 traits considered within a cereal plant breeding programme.
“Cost is another factor that comes into play, when assessing which aspects of overall performance should be emphasised within a new wheat or barley variety.
“It takes 14 years to take a plant breeding programme through from the initial cross, until the time when a new variety is brought to market.”
Bird said that the major gene STB6 is the one that has delivered the highest levels of inherent resistance to septoria amongst cereal crops grown under field conditions.
“But it is too impractical and costly to screen specifically for genetic resistance to septoria. So this leaves breeders with the option of combining the partial resistance inherent in their crossing programmes, thereby selecting new combinations of existing resistance levels.”
Looking to the future Bird said that plant breeders may come up new cereal varieties that have an inherent resistance.
“Many wild varieties of wheat are totally resistant to the disease,” he said.
“Work ongoing at the University of Nottingham is centred on the crossing of these feral strains with cultivated varieties. But it will probably take quite a number of years before this work can bring a commercially sustainable, septoria-resistant variety to the market.
“This work is being carried out using traditional plant breeding techniques. So the issue of GM does not come into play.”