Abstract: | The incidence of poplar mosaic virus evidenced by foliage symptoms, enzyme-linked immunosorbent assay (ELISA) or bioassay (infectivity) was greater in stooled clones having Aigeiros (especially as the female) parents than in those of Tacamahaca parentage. The overall prevalence of the virus in clones growing in England was less (84/344, 24%) than in clones growing in Poland (143/256, 56%). Whereas symptoms in PMV-infected P. deltoides were prominent and common, in P. nigra, another species assigned to the Section Aigeiros they were indistinct and rare. Evidence of poplar mosaic virus inferred from ELISA alone was found in only one aspen of 52 tested clones in the Sections Leuce, Leuce × Leuce or Leucoides. |