Extreme resilience of avocado sunblotch viroid RNA in sampled avocado leaves and fruit

The main purpose of the Avocado Nursery Voluntary Accreditation Scheme (ANVAS) in Australia is to prevent the spread of pathogens such as avocado sunblotch viroid (ASBVd) in planting material by implementing rigorous testing regimes for these pathogens during the propagation stages. There can sometimes be significant delays in delivery of a plant sample to the pathology laboratory for testing and the storage conditions may be suboptimal during transport. To address these concerns, experiments have been done to investigate how time and storage temperature affect the ability to detect ASBVd in leaf or fruit tissues. Most importantly, ASBVd was shown to be remarkably resilient and easily detected in detached avocado leaves, even when stored at room temperature for 4 weeks, during which time the leaves had become desiccated and necrotic.