New tool for detecting grapevine leafroll-associated virus 3

Leafroll is an economically significant disease of grapevines world-wide. The disease is associated with grapevine leafroll-associated virus 3 (GLRaV-3), which is the main causative agent of the disease and can be transmitted by insect vectors, clonal propagation and through grafting.

In New Zealand three mealybug species have been found to transmit the virus within and between vineyards and their control is integral to managing GLRaV-3. 

The disease is currently controlled by prevention (planting certified virus-tested vines) or by the removal of infected vines and the use of insecticides to control mealybug, however there is a growing preference for sustainable, integrated pest-management approaches. For GLRaV-3 this requires a better understanding of mealybug biology and virus-vector interactions. Key to this, is developing a virus detection tool which can effectively detect low amounts of the virus in a small insect.

In this study, scientists at Plant & Food Research developed two new molecular assays and compared them with three existing assays. One of these two, a new real-time molecular assay together with a hydrolysis probe, stood out above the other four as the most sensitive and reliable.

The Bio-protection Research Centre provided financial support for this study.

Journal Reference:McGreal B, Sandanayaka M, Chooi K, MacDiarmid R 2019 Development of sensitive molecular assays for the detection of grapevine leafroll‑associated virus 3 in an insect vector. Archives of Virology 164 2333-2338https://doi.org/10.1007/s00705-019-04310-0