Stem-pitting strains of Citrus tristeza virus reported in Croatia
In Croatia, citrus are grown along the Dalmatian coast and in some islands (covering approximately 1500 ha). The major species grown are Satsuma mandarins (Citrus unshiu) grafted on Poncirus trifoliata. The presence of Citrus tristeza virus (Closterovirus, CTV - EPPO A2 List) had previously been observed in the Neretva Valley. During characterization studies of isolates from Croatia, 15 samples (budsticks) were collected in autumn 2003 from the areas of Kastela, Split, Metkovic (Neretva Valley) and the island of Vis. These budsticks were grafted under glasshouse conditions onto indicator plants (C. sinensis cv. Madam Vinous) and symptoms were later observed. Typical symptoms of stem-pitting were observed with 4 CTV isolates collected from C. sinensis cvs. Fukumoto and Washington, C. unshiu cv. Ichimaru and C. wilsonii. In spring 2004, stem-pitting symptoms were observed in a Satsuma orchard in the Neretva Valley, thus confirming the occurrence of stem-pitting strains in Croatia. It is noted that most Satsumas were introduced into the Neretva region from Japan between 1964 and 1984, and that stem-pitting strains were probably introduced at the same time and have been spreading there for several decades.
Sources
Cerni S, Skoric D, Krajacic, Gatin Z, Santos C, Martins V, Nolasco G (2005) Occurrence of stem-pitting strains of Citrus tristeza virus in Croatia. Plant Disease 89(3), p. 342.