Apricot pseudo-chlorotic leaf spot virus: a new Trichovirus of stone fruit trees
During surveys done on Prunus material collected from Southern Italy which presented disease symptoms of unclear etiology, the presence of an unknown filamentous virus was found using a polyvalent PCR assay designed for the detection of Trichovirus, Capillovirus and Foveavirus. This virus was detected in mixed infection with Apple chlorotic leaf spot trichovirus (ACLVS) in 2 Japanese plum trees (Prunus salicina cv. Shiro) showing severe stem pitting or grooving symptoms, and in 1 apricot tree (P. armeniaca cv. Bulida) with symptoms resembling those of Apricot ringpox disease. This virus was characterized as a new and distinct species for which the name Apricot pseudo-chlorotic leaf spot virus is now proposed (to highlight its close relationship with ACLVS). Apricot pseudo-chlorotic leaf spot virus also has been found in several Prunus samples from France, Italy, Spain and Australia. In addition, preliminary comparisons of sequences suggested that it probably occurs in Jordan, Hungary, and Turkey. So far, it has been recovered only from a limited number of Prunus species (P. armeniaca, P. domestica, P. salicina, P. persica), but its host range needs to be further studied, particularly to determine whether it could infest other Prunus (e.g. cherry) and pome fruits (e.g. Cydonia, Malus, Pyrus). As this new virus has always been detected in combination with ACLVS, and associated with different types of symptoms, it is difficult to understand its pathogenicity. Further studies are needed to better understand the respective roles of ACLVS and Apricot pseudo-chlorotic leaf spot virus in disease expression.
Sources
Liberti D, Marais A, Svanella-Dumas L, Dulucq MJ, Alioto D, Ragozzino A, Rodoni B, Candresse T (2005) Characterization of Apricot pseudo-chlorotic leaf spot virus, a novel Trichovirus isolated from stone fruit trees. Phytopathology 95(4), 420-426.