BYDV Resistance in Wheat

BYDV symptoms in a wheat crop

The first field trials of advanced wheat lines that feature resistance to barley yellow dwarf virus (BYDV) were sown in the 2015-16 season. Two series of lines were developed using marker assisted selection to track the BYDV resistance into the milling wheat Viceroy and biscuit wheat Empress. These breeding lines were assessed for their field performance relative to the original Viceroy and Empress. The Viceroy selections were a fraction shorter, but had similar disease resistance qualities, test weight and grain protein content. These lines are currently undergoing milling quality testing. Unfortunately, all of the Empress selections were more susceptible to stripe rust and powdery mildew so have not been progressed.

Selections from an earlier generation of Empress crosses will be field trialled in the 2016-17 season. Once resistance to BYDV has been established in New Zealand adapted elite wheat backgrounds, they will be more easily incorporated into the main wheat breeding program through their use as parental lines.

Septoria Tritici Blotch Resistance in Wheat

Luisetti Seeds and Plant & Food Research are currently trying to obtain a series of wheat lines featuring the complete set of resistance genes to septoria tritici blotch (STB). Unfortunately, due to New Zealand’s strict biosecurity standards, it has been difficult to find international
collaborators that can meet the requirements to provide seed. A small set of lines has been obtained from AgCanada. This seed has been increased in the glasshouse and will be field trialed in the 2016-17 season.

STB is a major disease problem in wheat and there are documented cases of resistance to fungicides. Having wheat cultivars with genetic resistance to New Zealand pathotypes of STB is a key target for the Luisetti Seeds/Plant & Food Research wheat breeding programme.