Citrus tristeza closterovirus occurs in Jordan
In Jordan, citrus are mainly grown in the Jordan Valley. The most important species are sweet orange (Citrus sinensis), mandarin (C. reticulata), lemon (C. limon) and grapefruit (C. paradisi). Approximately 98% of these species are grafted onto sour orange rootstocks (C. aurantium) which are susceptible to tristeza. In the last few years, symptoms resembling those caused by CTV, including severe tree decline, yellowing and stunting have been observed in various orchards of the Jordan Valley. A survey was conducted in 2002 and 2003 on the possible presence of Citrus tristeza closterovirus (CTV - EPPO A2 list). More than 3000 trees in 62 orchards distributed in the central and northern parts of the Jordan Valley were individually inspected for symptoms. Leaf samples (in total 844) were collected in autumn and winter from symptomatic trees and tested (serological and molecular tests). Results showed that 12.7% and 15.2% of the samples from the central and Northern Jordan Valley, respectively, were infected by CTV. In addition, 100 leaf samples were collected from an orchard in the Dir Alla area (Central Jordan Valley) where severe symptoms were observed, and 49% of them tested positive for CTV. This study confirms the presence of CTV in the major citrus-growing regions of Jordan. It is stressed that this represents a serious risk to the Jordanian citrus industry. It is considered that epidemiological studies are urgently needed to determine which CTV strains and insect vectors are occurring in Jordan. It is also stressed that certification schemes and appropriate phytosanitary measures should be implemented.
The situation of Citrus tristeza closterovirus in Jordan can be described as follows: Present, a survey done in 2002/2003 has confirmed its presence in the Jordan Valley.
Sources
Anfoka GH, Abhary MK, Fattash I, Nakhla MK (2005) Occurrence and distribution of Citrus tristeza virus (CTV) in the Jordan Valley. Phytopathologia Mediterranea 44(1), 17-23.