VIEW ARTICLE

Resistance

Alleviation of Restricted Systemic Spread of Pepper Mottle Potyvirus in Capsicum annuum cv. Avelar by Coinfection with a Cucumovirus. John F. Murphy, Department of Plant Pathology, Auburn University, Auburn, AL 36849; Molly M. Kyle, Department of Plant Breeding, Cornell University, Ithaca, NY 14853. Phytopathology 85:561-566. Accepted for publication 17 January 1995. Copyright 1995 The American Phytopathological Society. DOI: 10.1094/Phyto-85-561.

In the resistant Capsicum annuum 'Avelar,' pepper mottle potyvirus (PepMoV) antigen accumulated in inoculated leaves but not in uninoculated leaves by 21 days postinoculation (dpi). The amount of PepMoV antigen in the inoculated leaves of Avelar was significantly less than that in comparable leaves from the susceptible control, C. annuum cv. NuMex R Naky. The accumulation and movement of PepMoV were examined using immuno-tissue blot analysis. PepMoV antigen was detected at 4 dpi in both genotypes in the inoculated central zone of the first two true leaves; however, PepMoV antigen was detected much sooner and at much higher concentrations in the uninoculated leaves of NuMex R Naky compared with Avelar. PepMoV was not detected in the first pair of uninoculated leaves by 25 dpi, although viral antigen was detected in the stem below the inoculated leaves and in the first internode above the inoculated leaves. When Avelar plants were coinfected with PepMoV and cucumber mosaic cucumovirus, PepMoV antigen accumulation was no longer restricted temporally or spatially within at least 50% of the Avelar plants.