Application of loop-mediated isothermal amplification in an early warning system for epidemics of an externally sourced plant virus

Authors

Benjamin S. Congdon, Department of Primary Industries and Regional Development WAFollow
Paul Matson, Department of Primary Industries and Regional Development WAFollow
Farhana Begum, Department of Primary Industries and Regional Development WA
Monica Kehoe, Department of Primary Industries and Regional Development WAFollow
Brenda A. Coutts, Department of Primary Industries and Regional Development WAFollow

Document Type

Article

Publication Date

5-27-2019

Journal Title

Plants

ISSN

2223-7747

Keywords

viruliferous aphid, diagnostic, insect trapping, Myzus persicae, turnip yellows virus, disease management, insecticide, decision support

Disciplines

Agronomy and Crop Sciences | Biosecurity

Abstract

Restricting Turnip yellows virus (TuYV) spread in canola (Brassica napus) crops often relies upon the application of systemic insecticides to protect young vulnerable plants from wide-scale green-peach aphid (GPA; Myzus persicae) colonization and subsequent virus infection. For these to be applied at the optimal time to ensure they prevent epidemics, growers would need to be forewarned of incoming viruliferous aphid migration and colonization. This study was conducted to field validate a loop-mediated isothermal amplification (LAMP) protocol designed to detect TuYV in aphids caught on traps and develop an early warning system for TuYV epidemics. Double-sided yellow sticky traps were deployed at 30 sites sown with canola over a two-year period in the south-west Australian grainbelt. Using LAMP, the percentage (%) of trap sides with TuYV-carrying aphids was measured and related to TuYV infection incidence in the adjacent crop. When TuYV was detected in aphids on >30% trap sides in a six-week period from pre-emergence to GS15 (five-leaf stage), TuYV reached >60% crop incidence by GS30 (beginning of stem elongation). Whereas, TuYV detection in aphids on ≤15% trap sides during this period was associated with ≤6% TuYV incidence by GS30. Furthermore, when large numbers of aphids, including GPA, were caught during this period but no TuYV was detected in them, minimal TuYV spread (≤5%) occurred in the crop by GS30. Therefore, the LAMP TuYV protocol can be used in an early warning system for TuYV epidemics by providing detection of initial viruliferous aphid migration into a canola crop before they establish colonies throughout the crop and spread virus. This would enable proactive, non-prophylactic, and thereby more effective systemic insecticide applications to minimize seed yield and quality losses due to early season TuYV infection.

Recommended Citation

Congdon, B S, Matson, P, Begum, F, Kehoe, M, and Coutts, B A. (2019), Application of loop-mediated isothermal amplification in an early warning system for epidemics of an externally sourced plant virus. Plants, 8 (5), 139.
https://library.dpird.wa.gov.au/bs_research/70