VIEW ARTICLE

Resistance

Alteration of Efficiencies of Acquisition and Inoculation of Watermelon Mosaic Virus 2 by Plant Resistance to the Virus and to an Aphid Vector. Louise R. Romanow, Department of Entomology, North Carolina State University, Raleigh 27695-7630; J. W. Moyer(2), and G. G. Kennedy(3). (2)Department of Plant Pathology, North Carolina State University; (3)Department of Entomology, North Carolina State University, Raleigh 27695-7630. Phytopathology 76:1276-1281. Accepted for publication 12 February 1986. Copyright 1986 The American Phytopathological Society. DOI: 10.1094/Phyto-76-1276.

The effects of aphid and virus resistance on acquisition and inoculation of watermelon mosaic virus 2 (WMV 2) were assessed using a colonizing (Aphis gossypii) and a noncolonizing (Myzus persicae) aphid species and three Cucumis melo genotypes. Together, these provided a treatment set containing all four combinations of plant resistance or susceptibility to aphids with resistance or susceptibility to virus. Plant resistance to WMV 2 reduced the efficiency of virus acquisition by both aphid species but had no detectable effect on inoculation efficiency. Virus acquisition efficiency was a function of virus concentration in the source plant and affected the probability of virus transmission by both aphid species similarly. Resistance to aphids reduced the efficiency of inoculation by A. gossypii, the resisted aphid, but not by M. persicae. Resistance to inoculation by A. gossypii without resistance to acquisition in the same genotype suggests that the requirements for aphid inoculation of viruses may differ from those for acquisition.