The Timor-Leste Directorate for Quarantine and Biosecurity (DNQB) manages plant biosecurity risk through biosecurity controls at international ports; and undertaking pest surveillance around ports and areas of agricultural production in Timor Leste. Pest surveillance activities are often undertaken in partnership with the Australian Department of Agriculture Fisheries and Forestry (DAFF) that is mutually beneficial for the partner plant biosecurity systems.
A key target for these surveys includes powdery mildew taxa that cause major damage to agricultural and ecological systems (Glawe 2008). Here we report on powdery mildew records, detected as part of joint DNQB-DAFF surveillance activity for 2022-2024. Symptomatic plants were collected from economically important crops and other plant species in Timor-Leste. Powdery mildew species were identified based on their morphology, host plants, and sequences of the Internal Transcribed Spacer (ITS) region of the nuclear ribosomal DNA (nrDNA). Morphological studies using light microscopy were focused on the characteristics of the asexual morph (anamorph) of the pathogens because the sexual morphs (teleomorphs) are only rarely or never produced in tropical regions.
The biosecurity implications and economic significance of these detections are discussed.
References: Glawe D. A. (2008). The powdery mildews: a review of the world's most familiar (yet poorly known) plant pathogens. Annu. Rev. Phytopathol. 46, 27–51. 10.1146/annurev.phyto.46.081407.104740 - DOI - PubMed
Acknowledgements: The authors acknowledge the contributions from Abel Ximenes from DNQB and Chris Rothwell from DAFF in assisting with collections and logistics for field work in Timor Leste; Rebecca James, Huma Safdar and Komal Gurdasani, from DAFF for assistance in processing of samples and undertaking DNA sequencing for some specimens.