Effects of tomato mosaic Tobamovirus infection on red spruce seedlings

Height, weight, root volume, shoot length, needle length and weight, and total chlorophyll content were measured for both control and tomato mosaic Tobamovirus (ToMV)-inoculated red spruce (Picea rubens Sarg.) seedlings in each of five, 3-month growth periods. Mean bud-break rating was determined for each seedling in growth period 5. In January 1995 the freezing tolerance of control and ToMV-infected seedlings was determined. Approximately 85% of the inoculated seedlings became infected with ToMV, as determined by enzyme-linked immunosorbent assay of young root tissue. Reduction in seedling height, weight, root volume, bud break, and mean shoot length of infected seedlings was observed when compared with control seedlings. The rate of increase over time in height, weight, and root volume was lower (54, 57, and 52%, respectively) in infected seedlings compared with control seedlings. Additionally, needles of infected seedlings were less susceptible to freezing damage than those of control seedlings. However, virus infection had no effect on the freezing tolerance of roots.