Development of real-time RT-PCR assays for the detection of Cucumber vein yellowing virus (CVYV) and Cucurbit yellow stunting disorder virus (CYSDV) in the whitefly vector Bemisia tabaci

Reverse transcription followed by real-time PCR assays based on TaqMan® chemistry have been developed for the detection and quantification of Cucumber vein yellowing virus (CVYV) and Cucurbit yellow stunting disorder virus (CYSDV) in individual adults of the whitefly vector Bemisia tabaci. The method includes an internal control for the detection of a gene from B. tabaci to compensate for variations in extraction efficiency. The assays designed were used to estimate proportions of viruliferous whiteflies collected from commercial greenhouse-grown crops in Spain. In a significant number of whiteflies, both viruses were detected and their amounts were estimated. The assays could be used to assist risk assessment of CVYV and CYSDV which constitute limiting factors in cucurbit crops. They are also suited to investigating the epidemiology and plant–virus–vector relationships in these diseases.