Effect of Turnip Mosaic Virus Infection on the Development, Virus Titer, Glucosinolate Concentrations, and Storability of Rutabaga Roots. L. W. Stobbs, Agriculture Canada, Research Station, Vineland Station, Ontario L0R 2E0. V. I. Shattuck, and B. J. Shelp. Department of Horticultural Sciences, University of Guelph, Guelph, Ontario N1G 2W1. Plant Dis. 75:575-579. Accepted for publication 13 November 1990. Copyright 1991 Department of Agriculture, Government of Canada. DOI: 10.1094/PD-75-0575.

Rows of rutabaga plants, grown in a greenhouse groundbed, were inoculated with turnip mosaic virus (TuMV) at 2-wk intervals during root development. Plants inoculated within 12 wk after seeding produced unmarketable roots that were small and elongated with severe goosenecking of the upper root and stem. Dry matter content of healthy roots and roots infected at different stages in their development did not differ significantly. Infected roots contained low levels of virus, independent of the stage of root development at which they were inoculated. The presence of TuMV in roots and decay of the roots in storage were not correlated. Roots infected early in their development contained higher concentrations of total glucosinolates, compared with roots infected later. These glucosinolates decreased in concentration as the root size increased. The concentration of 2-hydroxy-3-butenyl glucosinolate was higher in inoculated plants than in uninoculated plants, whereas other glucosinolates were unaffected or reduced in concentration in inoculated plants. Such alterations in glucosinolate metabolism may result in flavor changes and metabolic breakdown products, such as 5-vinyloxazolidine-2-thione, resulting from the hydrolysis of 2-hydroxy-3-butenyl glucosinolate, a potent goitrogen.