FIG. 1.

Maximum-likelihood trees depicting the phylogenetic relationships of 20 BFDV isolates ignoring recombination between isolates (a) and with major recombinant regions removed from individual sequences (b). The full-length tree was rooted by using three nonpsittacine avian circoviruses (canary circovirus [GenBank accession number AJ301633], columbid circovirus, [AJ298229], and goose circovirus [AJ304456]). Only the subtrees containing the BFDV isolates are shown. Bootstrap values were calculated by using the neighbor-joining method based on the two-parameter corrected distance matrix. The major virus genotypes are bracketed and identified by roman numerals I to VIII.