Infection of red spruce, black spruce, and balsam fir seedlings with tomato mosaic virus

Red spruce (Picearubens Sarg.), black spruce (Piceamariana (Mill.) B.S.P.), and balsam fir (Abiesbalsamea (L.) Mill.) seedlings were root inoculated with tomato mosaic virus, potted, and maintained in a cold frame. The virus was detected by enzyme-linked immunosorbent assay in root extracts of several inoculated seedlings of each species 6–12 months postinoculation, and in root extracts of approximately 35–40% of both inoculated and noninoculated seedlings of each species 12–18 months postinoculation. Virus spread apparently occurred from the roots of infected to noninfected seedlings within the cold frame. The presence of virus in root extracts was confirmed by immunoelectron microscopy. The virus was not detected in the needles of any seedling at any time by either enzyme-linked immunosorbent assay or immunoelectron microscopy. A transitory needle chlorosis was observed in approximately 14% of the inoculated black spruce and 30% of the inoculated red spruce seedlings, but tomato mosaic virus was not det...