Navelina ISA 315: A cultivar resistant to citrus variegated chlorosis

- 'Navelina ISA 315' plants remained asymptomatic after 10 years of field transplanting.
- 'Pêra' “IAC” plants showed high concentration of X. fastidiosa.
- 'Navelina ISA 315' seedlings inoculated with X. fastidiosa did not show symptoms.

Citrus variegated chlorosis (CVC), caused by Xylella fastidiosa, is a bacterial disease of great importance to the Brazilian citrus industry. CVC is transmitted by grafting and by leafhoppers of the Cicadellidae and Cercopidae families. There is little information about CVC tolerant sweet orange cultivars (Citrus sinensis L. Osbeck). However, previous studies have indicated some resistance to CVC in the 'Navelina ISA 315' cultivar. Based on such information, this study has been carried out to determine the resistance of 'Navelina ISA 315' to CVC observing disease symptoms in the field and in the greenhouse, associated with the presence and quantitation of X. fastidiosa in plant tissue by PCR and quantitative real time PCR (qPCR). In agreement with previous information, the results show that 'Navelina ISA 315' is resistant to CVC, on the grounds that almost no symptoms and low bacterial concentrations were found.