Irregular Distribution of Tomato Ringspot Virus in Apple Trees. M. W. Bitterlin, Graduate Student, Department of Plant Pathology, New York State Agriculture Experiment Station, Cornell University, Geneva 14456. D. Gonsalves, Associate Professor, Department of Plant Pathology, and J. N. Cummins, Professor, Department of Pomology and Viticulture, New York State Agriculture Experiment Station, Cornell University, Geneva 14456. Plant Dis. 68:567-571. Accepted for publication 3 January 1984. Copyright 1984 The American Phytopathological Society. DOI: 10.1094/PD-68-567.

Leaf, bark, and root samples of Malling-Merton 106 (MM 106) and cultivar/MM 106 trees were assayed for tomato ringspot virus (TmRSV) by enzyme-linked immunosorbent assay (ELISA) at various times during the growing season. TmRSV was not regularly distributed within trees. In MM 106 trees, TmRSV was detected most consistently in leaves, slightly less so in bark, and only erratically in roots. The average absorbance values at 405 nm declined toward the end of the growing season and were always highest in leaves and lowest in roots. TmRSV was also detected in Golden Delicious bark tissue just above the graft union. The location and/or mode of inoculation seemed to influence the virus distribution within the trees.