Developing aphid resistant legumes is getting closer by using Medicago, one of the ‘models’ of the plant world.

Legume crops reap $675 million per year in Australia in grain value alone – add their ability to fix nitrogen and break cereal disease cycles and their value soars to over $1 billion. Legume based pastures are worth billions.

But aphids can cause devastating losses in both legume crops and legume-based pastures.

Dr Karam Singh and a CSIRO team in Perth have identified aphid resistance in Medicago and are now identifying the genes responsible for it.

Medicago has much in common with all legumes yet it is much easier for scientists to work with than commercial legume species.

Current methods for dealing with aphids, namely pesticides, are often too costly – limiting the industry’s ability to produce legumes for human consumption and stock feed.

If aphid resistant genes can be identified in Medicago it will be much easier to find the equivalent genes in commercial legumes to help breed aphid-resistant legume crops and pastures.

Different defence mechanisms used by legumes to fend off aphids have also been identified which could lead to innovative and effective ways to address aphids too.

This research was supported in part by the Grains Research and Development Corporation and the Australian Government Department of Education, Science and Training.

Source: CSIRO Plant Industry newsletter