Bacterial wilt <i>Corynebacterium insidiosum</i> (McCulloch, 1925) Jensen, 1934 of lucerne in New zealand

Abstract

Abstract Yellow‐green plants with mottling and cupping of leaflets and stunted growth were found in lucerne ( Medicago sativa L.) stands in Mid‐Canterbury. A bacterium, isolated from infected plants, produced typical symptoms of the disease when inoculated by three methods into lucerne plants under glass. The bacterium was consistently reisolated from such plants. From morphological and biochemical tests the pathogen was identified as Corynebacterium insidiosum (McCulloch, 1925) Jensen, 1934. ‘Wairau’, the main lucerne variety in New Zealand, was susceptible, whereas resistant varieties from U.S.A. were confirmed as resistant to New Zealand isolates.