Development and validation of a real-time RT-PCR test for screening pepper and tomato seed lots for the presence of pospiviroids.

Potato spindle tuber viroid and other pospiviroids can cause serious diseases in potato and tomato crops. Consequently, pospiviroids are regulated in several countries. Since seed transmission is considered as a pathway for the introduction and spread of pospiviroids, some countries demand for the testing of seed lots of solanaceous crops for the presence of pospiviroids. A real-time RT-PCR test, named PospiSense, was developed for testing pepper (Capsicum annuum) and tomato (Solanum lycopersicum) seeds for seven pospiviroid species known to occur naturally in these crops. The test consists of two multiplex reactions running in parallel, PospiSense 1 and PospiSense 2, that target Citrus exocortis viroid (CEVd), Columnea latent viroid (CLVd), pepper chat fruit viroid (PCFVd), potato spindle tuber viroid (PSTVd), tomato apical stunt viroid (TASVd), tomato chlorotic dwarf viroid (TCDVd) and tomato planta macho viroid (TPMVd, including the former Mexican papita viroid). Dahlia latent viroid (DLVd) is used as an internal isolation control. Validation of the test showed that for both pepper and tomato seeds the current requirements of a routine screening test are fulfilled, i.e. the ability to detect one infested seed in a sample of c.1000 seeds for each of these seven pospiviroids. Additionally, the PospiSense test performed well in an inter-laboratory comparison, which included two routine seed-testing laboratories, and as such provides a relatively easy alternative to the currently used tests

Tomato Brown Rugose Fruit Virus Nextstrain Build Version 3: Rise of a Novel Clade

In the Netherlands, tomato brown rugose fruit virus (ToBRFV; genus Tobamovirus) was first identified in tomato crops in 2019. Since then, the National Plant Protection Organization (NPPO-NL) has performed surveys to track and trace this regulated virus aiming for its eradication. To gain more insight in the epidemiology of ToBRFV, genomes were assembled from Illumina sequence data. Whole-genome phylogenetics was integrated with epidemiological metadata in a Nextstrain build. Two new clades were defined, one of which displayed a rapid increase in comparison to the previous version of the Nextstrain build. This rapid increase could be attributed to the unauthorized application of an isolate of ToBRFV as a cross-protection product. Further analysis of the test results of positive samples from tomato production sites suggests that both deliberate application and accidental introduction had occurred. This report introduces the inclusion of 61 new (near) complete ToBRFV genomes in version three of the Nextstrain build, available from https://nextstrain.nrcnvwa.nl/ToBRFV/20220412. [Graphic: see text] Copyright © 2023 The Author(s). This is an open access article distributed under the CC BY 4.0 International license

C4d Staining In Renal Allograft Biopsies with Early Acute Rejection and Subsequent Clinical Outcome

Nephrolog