Further studies on the citrus chlorotic dwarf disease found in Turkey
In the late 1980s, a new disease of citrus, called citrus chlorotic dwarf, was observed in the Eastern Mediterranean region of Turkey (EPPO RS 94/209). Symptoms observed are characterized by leaf deformation, chlorotic flecking of interveinal tissues and oak leaf patterns. Although these symptoms resemble those caused by citrus leaf rugose ilarvirus or citrus variegation ilarvirus, it was found that these viruses are not associated with citrus chlorotic dwarf. On citrus hosts, the disease seems to be transmitted by Parabemisia myricae, grafting and cutting tools, but not by sap inoculation. However, from leaf samples of citrus affected by chlorotic dwarf, a virus was consistently transmitted by sap inoculation to herbaceous hosts. Serological studies showed that this virus was similar, if not identical, to olive latent virus 1. The authors have considered it as a citrus isolate of olive latent virus 1, which was found 10 years ago in Southern Italy on symptomless olive trees. At that time, it was thought to be a sobemovirus. Further studies on the properties (biological, morphological, physio-chemical etc.) of this citrus isolate of olive latent virus 1 (OLV-1/Tk), showed that it could be regarded as a new necrovirus species. But when assessing the occurrence of the virus in citrus grown in the field (showing symptoms or not), OLV-1/Tk was identified in 59 % of the citrus plants affected by citrus chlorotic dwarf and in 28 % of symptomless plants. The authors concluded that their results did not support the hypothesis that citrus chlorotic dwarf disease is due to OLV-1/Tk, but the frequent association of this virus with diseased plants remains intriguing.
Sources
Martelli, G.P.; Yilmaz, M.A.; Savino, V.; Baloglu, S.; Grieco, F.; Güldür, M.E. (1996) Properties of a citrus isolate of olive latent virus 1, a new necrovirus.
European Journal of Plant Pathology, 102(6), 527-536.