Evidence that Broad Bean Yellow Band Virus Is a New Serotype of Pea Early-browning Virus

Abstract

SUMMARY Nucleic acid hybridization tests with cDNA made by the random priming method showed that broad bean yellow band virus (BBYBV) is as closely related to the British and Dutch serotypes of pea early-browning virus (PEBV-B and PEBV-D) as they are to one another. No relationship was detected between BBYBV and either of two other tobraviruses, tobacco rattle and pepper ringspot viruses. BBYBV, PEBV-B and PEBV-D shared extensive nucleotide sequences in their larger genome segment (RNA-1) but differed greatly in the sequences in their RNA-2 and in the antigenic relatedness of their particles. Pseudorecombinant isolates were obtained by re-assorting the genome parts of PEBV-B and PEBV-D with those of BBYBV, which seems best considered as a third serotype of PEBV, designated PEBV-BBYB. The properties of the pseudorecombinants indicated that particle protein specificity and some symptoms in test plants are controlled by RNA-2. Other symptoms induced by the pseudorecombinants were unlike those of the parental strains, implicating both RNA-1 and RNA-2 in their genesis.