Grains Research and Development

Date: 01.09.2002

Biotech assists breeding for resistance and quality

CLlMA's Oonagh Byrne with seed pods from a P. fulvum derived line, back-crossed with the commercial field pea variety Helena as her GRDC project closes in on a pea weevil-resistant pea.

UNTAMED RELATIVES may end up saving Australian graingrowers from the devastating impacts of pea weevil.

Pea weevil infests up to 30 per cent of the national field pea crop, resulting in export rejection and diminished quality of one of Australia's highest-yielding pulses.

Field pea yields consistently match lupin, but the normally lucrative $300/ha return can be slashed by $40/ha with a bad weevil infestation.

In response, Darryl Hardie of the WA Department of Agriculture and Oonagh Byrne from the Centre for Legumes in Mediterranean Agriculture (CLIMA) have examined field pea's wild cousin, Pisum fulvum, to bring across its pea weevil resistance.

Selecting resistance

Although highly resistant to pea weevil, P.fulvum produces undersized seeds and is poorly adapted to local agronomy, which means the GRDC project must be careful to transfer only the pest resistance to commercial field peas.

"Molecular markers have been used to identify the resistance trait in P.fulvum and a genetic profile developed for the wild and cultivated pea, so that when we make crosses we can select against poor per-formance characteristics," Ms Byrne said.

Using techniques developed in previous GRDC-supported research, Ms Byrne developed a PCR-based assay for molecular markers associated with pea weevil resistance. These are undergoing laboratory testing and promise to help identify lines that breeders can use as parental material to transfer resistance into commercial field peas. The aim is for resistance without diminished quality.

Ms Byrne's research was supported by the GRDC's Crop Improvement program, which aims to better understand and deploy disease-resistance genes to develop more productive and robust legume crops for growers.

Program 3

Contact: Ms Oonagh Byrne, CLIMA 0893801981