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Reverse transcription-polymerase chain reaction (RT-PCR) is an effective method for detecting the presence of viroids in plant tissue. Viroid RNA is converted to cDNA and amplified to detectable levels, making it a fast and useful detection tool, even when the viroid is present at low levels. Methods of viroid detection using conventional RT-PCR are described in this chapter., (© 2022. Springer Science+Business Media, LLC, part of Springer Nature.)

An apscaviroid, tentatively named citrus viroid VII (CVd-VII), was recently discovered in citrus in Australia. A diagnostic assay using real-time reverse transcription polymerase chain reaction was developed and validated to detect the viroid in citrus plants. The assay showed a high level of sensitivity, reliably detecting 2000 plasmid copies per reaction, while down to 20 plasmid copies per reaction were occasionally detected. The assay showed high specificity, producing no false positives or cross-reactivity with a range of other citrus graft-transmissible pathogens, including viroids, viruses and bacteria. The real-time assay was also found to be more sensitive than the available end-point reverse transcription polymerase chain reaction assay by a factor of 100,000 and could be a useful tool for the rapid detection of CVd-VII in diagnostic and research environments., (Copyright © 2021 Elsevier B.V. All rights reserved.)

A novel citrus viroid was discovered in a non-symptomatic Lisbon lemon (Citrus x limon L. Burm.f.) tree in New South Wales, Australia. Bioindexing, molecular detection and characterization involving sequencing combined with in silico analysis for the identification of the viroid-RNA hallmark properties of transmissibility and autonomous replication as well as specific sequence and structural motifs suggest that this viroid is a member of a new species in the genus Apscaviroid, family Pospiviroidae, which we have tentatively named "citrus viroid VII" (CVd-VII).

This article reports the first record of coleus blumei viroid 1 (CBVd-1) in Australia. The viroid was detected in an asymptomatic coleus plant sample obtained from New South Wales. Further analysis confirmed the presence of CBVd-1 in multiple samples, and the viroid was identified through high throughput sequencing. CBVd-1 is a predominant species in the genus Coleviroid and has been reported worldwide. More surveys are needed to determine if CBVd-1 is the only coleus-infecting viroid in Australia. The research was funded by CAUL and its Member Institutions, and the data is publicly available. [Extracted from the article]