Emaravirus Emaravirus Emaravirus is a genus of plant viruses. The genus has more than six species, including: "European mountain ash ringspot-associated virus" (type species), "Fig mosaic virus", "Pigeonpea sterility mosaic virus", "Raspberry leaf blotch virus", "Rose rosette virus" and Maize red stripe virus. "European mountain ash ringspot-associated virus" is associated with a leaf mottling and ringspot disease of European mountain ash "Sorbus aucuparia". It can be transmitted by grafting and possibly mites. The virion particle is between 80-100 nm and consists of an enveloped ribonucleocapsid that exhibits helical symmetry. The genomes are segmented, consisting of four strands of negative-sense single-stranded RNA.
Fraxinus excelsior narrow crown. The bark is smooth and pale grey on young trees, becoming thick and vertically fissured on old trees. The shoots are stout, greenish-grey, with jet black buds (which distinguish it from most other ash species, which have grey or brown buds). The leaves are opposite, long, pinnately compound, with 7–13 leaflets with coarsely serrated margins, elliptic to narrowly elliptic, long and broad and sessile on the leaf rachis. There are no stipules. These features distinguish ash from mountain ash ("Sorbus aucuparia") in which the leaves are alternate with paired stipules. The leaves are often among the last to