A plant virus that partially protects its wild legume host against herbivores

Seedlings of Kennedya rubicunda were manually inoculated with Kennedya yellow mosaic virus and planted along with comparable virus-free seedlings in a coastal bushland site where the plant and virus were common. Virus infection decreased the growth rate of the plants by about one-third; however, virus-free plants disappeared more than twice as quickly as infected plants as a result of grazing by herbivores. In palatability trials using grated carrot bait, caged young rabbits preferred bait mixed with powdered virus-free K.rubicunda leaves to that mixed with virus-infected leaf powder. However, 'polyamine extracts' of the leaves did not have a comparable effect.