The occurrence of bacterial leaf blight in wild and cultivated rice in northern Australia

Abstract

Bacterial leaf blight (Xanthomonas oryzae) of rice is reported for the first time in Australia, where it occurred on cultivated rice and also on the indigenous wild rice species Oryza rufipogon and O. australiensis in the Northern Territory. The pathogen was isolated, characterized, and tested in Hawaii on a differential set of rice cultivars. All Australian isolates of X. oryzae had a lower average virulence, and a distinct pattern of virulence, in comparison with about 200 isolates from 10 Asian countries. The Australian isolates may represent a separate pathotype of X. oryzae, which suggests that the pathogen is indigenous and not recently introduced into northern Australia.