Citrus variegated chlorosis (Xylella fastidiosa) is not transmitted by citrus seeds
In Brazil, experiments have been conducted over a period of 7 years to evaluate the possible seed-to-seedling transmission of Xylella fastidiosa (EPPO A1 List) in sweet orange (Citrus sinensis). On this host, the bacterium causes a disease known as citrus variegated chlorosis. The bacterium was found colonizing the fruit (exocarp, central axis and mesocarp) and seed parts (seed coat, endosperm and embryo). However, X. fastidiosa was never detected (PCR) in seedlings grown from infected seeds. The authors concluded that these results indicate that X. fastidiosa is not transmitted from seeds to seedlings (Della Colletta-Filho et al., 2014). Another seed transmission study, also carried out in Brazil on sweet oranges and lemons (C. sinensis and C. limon), came to the same conclusion (Cordeiro et al., 2014).
Cordeiro AB, Sugahara VH, Stein B, Leite Junior RP (2014) Evaluation by PCR of Xylella fastidiosa subsp. pauca transmission through citrus seeds with special emphasis on lemons (Citrus limon (L.) Burm. F). Crop Protection 62, 86-92.
Della Coletta-Filho H, Alves Carvalho S, Carvalho Silva LF; Machado MA (2014) Seven years of negative detection results confirm that Xylella fastidiosa, the causal agent of CVC, is not transmitted from seeds to seedlings. European Journal of Plant Pathology 139(3), 593-596.