A new tospovirus species infecting Solanum esculentum and Capsicum annuum in Thailand

Based on distinct sequences, serology and host range, isolates of a new tospovirus species infecting field crops of tomato and pepper in Thailand are shown to be members of the provisionally named Tomato necrotic ringspot virus. © Australasian Plant thology ociety 2010

Multiplex Detection of Plant Pathogens Using a Microsphere Immunoassay Technology

Plant pathogens are a serious problem for seed export, plant disease control and plant quarantine. Rapid and accurate screening tests are urgently required to protect and prevent plant diseases spreading worldwide. A novel multiplex detection method was developed based on microsphere immunoassays to simultaneously detect four important plant pathogens: a fruit blotch bacterium Acidovorax avenae subsp. citrulli (Aac), chilli vein-banding mottle virus (CVbMV, potyvirus), watermelon silver mottle virus (WSMoV, tospovirus serogroup IV) and melon yellow spot virus (MYSV, tospovirus). An antibody for each plant pathogen was linked on a fluorescence-coded magnetic microsphere set which was used to capture corresponding pathogen. The presence of pathogens was detected by R-phycoerythrin (RPE)-labeled antibodies specific to the pathogens. The assay conditions were optimized by identifying appropriate antibody pairs, blocking buffer, concentration of RPE-labeled antibodies and assay time. Once conditions were optimized, the assay was able to detect all four plant pathogens precisely and accurately with substantially higher sensitivity than enzyme-linked immunosorbent assay (ELISA) when spiked in buffer and in healthy watermelon leaf extract. The assay time of the microsphere immunoassay (1 hour) was much shorter than that of ELISA (4 hours). This system was also shown to be capable of detecting the pathogens in naturally infected plant samples and is a major advancement in plant pathogen detection

Epidemiology of Tospoviruses in South and Southeast Asia: Current status and future prospects

Tospoviruses are emerging as a major constraint to the production of a broad range of economically important crops in South and Southeast Asia (S & SEA). Available data suggest that the majority of these viruses belong to serogroup IV (Watermelon silver mottle virus serogroup). Many of these viruses show geographical structuring in that they are restricted to the Asian continent. In recent years, tospovirus species like Capsicum chlorosis virus and Iris yellow spot virus, present in other continents, have been reported in the S & SEA region. Among different species of thrips (Thysanoptera: Thripidae) that have been confirmed as vectors of one or more tospoviruses worldwide, only a few have been authenticated to be present in the S & SEA region. The current knowledge on the distribution of thrips vectors and tospoviruses in the region will be reviewed and the research needs for a better understanding of the growing impact of tospoviruses and thrips vectors will be discussed