Link to home

Evaluation of Inoculation Methods for Screening Horseradish Cultivars for Resistance to Verticillium dahliae

April 1997 , Volume 81 , Number  4
Pages  356 - 362

N. Atibalentja and D. M. Eastburn , Department of Crop Sciences, University of Illinois, Urbana 61801



Go to article:
Accepted for publication 20 December 1996.
ABSTRACT

Four inoculation methods—colonized oatseed, root dip, infested soil, and set dip—were tested in the greenhouse for their effectiveness in identifying horseradish cultivars that are resistant to Verticillium wilt of horseradish. Examination of the inoculum density-disease relationships derived with each of these methods on susceptible (647A) and resistant (769A) cultivars showed that all were effective, though at varying degrees, in differentiating between susceptible and resistant reactions. Results were more consistent with the root dip method as it produced the largest least-squares means difference in wilt index between the two cultivars, the highest r 2, the lowest coefficient of variation, the shortest incubation periods, and the highest incidence of foliar symptoms. Overall, inoculum concentrations accounted for only a small amount of the total variation in wilt index (0.14 ≤ r 2 ≤ 0.73). This observation, in accord with previous reports on other hosts of Verticillium dahliae, would suggest that inoculum densities may not be a good predictor of the severity of Verticillium wilt of horseradish.



© 1997 The American Phytopathological Society