Section outline
-
EMARaV (genus Emaravirus, family Fimoviridae) is a single stranded RNA virus with a negative orientation (Rehanek et al. 2022). The virus genome consists of six RNAs (von Bargen et al. 2019) which are encapsidated by the virus-encoded nucleoprotein. The nucleocapsids are protected by a lipid-double membrane with integrated glycoproteins, thus forming the spherical particles of varying size (80-100 nm). Due to its molecular and morphological characteristics EMARaV, was the first member of the newly established genus Emaravirus.
Although the ringspot disease of rowan was already first described in 1957 in Finland (Jamalainen 1957) and the virus has been identified as causal agent in 2007 (Mielke & Mühlbach, 2007) several questions regarding the epidemiology of EMARaV need further research. The host range as well as the modes of transmission for instance (by pollen and seed, vector species involved, water, root connation etc.) has to be investigated, in order to explain the part of vector- and seed-, water- and soil transmission in the wide geographical distribution of the ringspot disease of rowan as well as the impact of the virus on the vitality of virus-infected trees.
EMARaV-infected bastard serviceberry (Karpatiosorbus x hybrida, syn. S. rotundifolia) showing chlorotic line pattern, spots, and mottle.