black raspberry necrosis virus black raspberry necrosis virus black raspberry necrosis virus (brnv) is a plant pathogen virus of the genus sadwavirus found in black raspberries (rubus occidentalis). the virus causes leaf chlorosis, mottling and puckering. affected plants typically fail to yield fruits after three to four years. black raspberry necrosis virus virus classification (unranked): virus realm: riboviria kingdom: orthornavirae phylum: pisuviricota class: pisoniviricetes order: picornavirales family: secoviridae genus: sadwavirus subgenus: stramovirus species: black raspberry necrosis virus synonyms black raspberry mild mosaic virus raspberry black necrosis virus