A New Primer Set for the Efficient Detection of Spiroplasma citri, the Causal Agent of Citrus Stubborn Disease

Citrus stubborn disease caused by Spiroplasma citri is a limiting factor for citrus production in countries with desert or semi-arid conditions in the Mediterranean basin. In order to develop a PCR assay specific and sensitive for detecting Mediterranean S. citri strains, three new PCR primers were designed based on repetitive sequences annotated as "Hypothetical proteins". The primer pairs were evaluated for their sensitivity to detect S. citri using a PCR assay with serial dilutions of positive cultures and DNA extracted from S. citri infected plants, while specificity was determined by PCR using DNA extracted from cultures of other Spiroplasma species.