Western Australian researchers are racing to produce lupins resistant to a growing viral threat, which can cut yields by more than 60 per cent.

A new non-necrotic strain of Bean Yellow Mosaic Virus (BYMV) emerged in Western Australia a few years ago and is spreading rapidly. Like traditional BYMV, the new strain knocks yields but, unlike its cousin, does not kill the plant, which remains as a disease donor for neighbouring crops.

However, recent trials at the Centre for Legumes in Mediterranean Agriculture (CLIMA) have tested new first generation cultivars for resistance to the virus.

"The industry needs good varieties to fight this devastating new virus strain. If we can develop a resistant lupin variety, we can corner the virus in susceptible ones and eventually halt its spread," Western Australia State Agricultural Biotechnology Centre based CLIMA researcher, Steve Wylie claimed.

With support from the Grains Research and Development Corporation, Dr Wylie, Dr Sue Barker (Lecturer at the School of Plant Biology, University of Western Australia), Simone Chapple (Research Assistant, CLIMA) and their CLIMA based research team have been developing and testing transgenic virus-resistant lupins for four years.

Before inserting part of a BYMV gene, they bent it into a hairpin loop that primed the plant’s immune system to recognise and destroy the virus.

The process is analogous to vaccination in humans and similar to the technique CLIMA is using to develop cucumber mosaic virus resistance in lupins and chickpeas.

From 5000 attempts to install the new gene, 130 lupin plants emerged with it located at different points in their genome -- a gene transfer rate five times higher than usual.

"The Agrobacterium we use to transfer genes into lupins is sometimes recognised as a disease pathogen and rejected, preventing gene insertion. To ease transfer, we used an older lupin variety (Merrit), with less robust defence mechanisms than new varieties," Dr Wylie explained.