New diseases of fruit trees
At the ISHS International Symposium on virus diseases of fruit trees (Bethesda, US, 1997-06-23/27), the following new or newly characterized diseases of fruit trees were reported.
- Cherry A capillovirus
Cherry A capillovirus has recently been identified and characterized as a new virus in sweet cherry. Preliminary surveys indicated a wide distribution of the virus in sweet cherry sources from Europe and Canada. However, no data are given on the impact of this virus. (James ; Jelkmann, 1997; Eastwell ; Bernardy, 1997)
- Olive witches’ broom disease
A new olive disorder has recently been reported in Central Italy. Diseased plants showed dwarfed branches with shortened internodes, leaf deformation and chlorosis, proliferation of axillary buds with witches’ broom. Phytoplasmas were detected in affected trees. Preliminary investigations on the entomofauna revealed the presence of several potential vectors of phytoplasmas, including some specimens of the genus Hyalesthes (known to be a vector of phytoplasmas). This disease has been observed in many olive orchards in central Italy, and is causing severe economic problems (Del Serrone ; Barba, 1997).
- Stocky prune nepovirus
In several regions of south-western France, a disease of plum characterized by shortened internodes in spring, chlorotic and rolled leaves, small fruits which drop rapidly has been observed for a long time, particularly on Prune d’Ente (used for dried prune production). This disease has a limited impact and geographical distribution. It has been diversely named: stocky prune disease, dégénérescence du Prunier d’Ente, maladie du prunier stérile, maladie des pruniers mâles, maladie de Brugères. Epidemiological observations indicated that a soil-borne virus could be responsible of the disease. Recent studies have shown that a previously unknown virus is associated with the disease, it has been characterized and the name stocky prune nepovirus has tentatively been proposed (Candresse et al., 1997).
Sources
Candresse, T.; Desvignes, J.C.; Delbos, R.P.; LeGall, O.; Dunez, J. (1997) Characterization of stocky prune virus, a new nepovirus detected in French plums. Abstract of a paper presented at the ISHS XVII International Symposium on virus diseases of fruit trees, Bethesda, US, 1997-06-23/27, p 112-113.
Del Serrone, P.; Barba, M. (1997) Olive witches’ broom: a new olive disorder associated with phytoplasmas. Abstract of a paper presented at the ISHS XVII International Symposium on virus diseases of fruit trees, Bethesda, US, 1997-06-23/27, p 119.
Eastwell, K.C.; Bernardy, M.G. (1997) Relationship of cherry virus A to little cherry disease in British Columbia. Abstract of a paper presented at the ISHS XVII International Symposium on virus diseases of fruit trees, Bethesda, US, 1997-06-23/27, p 118.
James, D.; Jelkmann, W. (1997) Detection of cherry virus A in Canada and Germany. Abstract of a paper presented at the ISHS XVII International Symposium on virus diseases of fruit trees, Bethesda, US, 1997-06-23/27, p 117.