Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract

First report of Sarocladium oryzae causing sheath rot on rice (Oryza sativa) in Western Australia.

Abstract

In 2011, a sheath rot of rice was observed in the Ord River Irrigation Area in northern Western Australia. Symptoms were variable, appearing as either (i) oblong pale to dark brown lesions up to 3 cm in length, (ii) lesions with pale grey/brown centres and with dark brown margins, or (iii) diffuse dark or reddish brown streaks along the sheath. Lesions enlarged and coalesced, often covering the majority of the leaf sheath, disrupting panicle emergence. Amplification of the internal transcribed spacer (ITS) 1 and (ITS) 2 regions flanking the 5.8S rRNA gene was conducted with universal primers ITS1 and ITS4. The DNA PCR products from a single isolate were sequenced and BLAST analyses were used to compare sequences with those in the GenBank. The sequence had 99% nucleotide identity with the corresponding sequence in the GenBank for S. oryzae. Isolates showed morphological (conidiophore and conidia characteristics) and molecular similarities with S. oryzae. This is thought to be the first report of this pathogen in Western Australia.