Detection methods (RT-PCR and DAS-ELISA) for citrus psorosis-ringspot virus
Psorosis is a damaging disease of citrus whose etiology is still unclear. Two types of leaf symptoms have been described (chlorotic flecking and ringspot). Two names have been proposed: citrus-psorosis associated virus and citrus ringspot virus (EU Annex II/A1), to describe isolates of what is considered by several authors as being probably one virus. Detection methods (RT-PCR and DAS-ELISA) were developed to detect an isolate of citrus ringspot virus (CtRSV-4) from Florida, and were then tested to see how they could be used to detect 20 other isolates (including citrus ringspot, psorosis A and B). The PCR and ELISA methods were both successful in detecting CtRSV-4, but other isolates were less sensitively and reliably detected. However, 5 isolates could be detected by PCR and 17 by ELISA, which suggests that psorosis disease is commonly associated with virus strains that are fairly closely related to CtRSV-4. The authors concluded that both ELISA and PCR methods can be used for detection of a range of psorosis isolates, but that variation of the pathogens involved in the field might cause problems for these diagnostic tests.
Sources
Garcia, M.L.; Sanchez de la Torre, M.E.; Dal Bo, E.; Djelouah, K.; Rouag, N.; Luisoni, E.; Milne, R.G.; Grau, O. (1997) Detection of citrus psorosis-ringspot virus using RT-PCR and DAS-ELISA.
Plant Pathology, 46(6), 830-836.