Effect of Interaction Between Two Viruses and Rhizoctonia on Pepper. D. J. Pieczarka, Assistant Plant Pathologist, University of Florida, Agricultural Research and Education Center, Belle Glade 33430. T. A. Zitter, Associate Professor, Department of Plant Pathology, Cornell University, Ithaca, NY 14853. Plant Dis. 65:404-406. Copyright 1981 American Phytopathological Society. DOI: 10.1094/PD-65-404.

An atypical strain of tobacco mosaic virus (designated TMV-P) isolated from pepper caused systemic infection of pepper cultivars with and without the L-gene for the local necrotic reaction. A typical isolate of TMV from tomato caused systemic symptoms on cultivars lacking the L-gene. Host range reactions indicated that TMV-P is probably synonymous with Samsun latent TMV. In mixed infections of TMV-P and pepper mottle virus (PeMV), the systemic movement of PeMV was increased in PeMV-tolerant Delray Bell peppers. Mixed infections with TMV-P did not cause a breakdown of resistance of Florida VR-2 peppers to potato virus Y or tobacco etch virus. Early Calwonder peppers infected with TMV-P and PeMV were more susceptible to Rhizoctonia damping-off. Mixed viral infections (TMV-P and PeMV) were no more effective than single infections in increasing pepper susceptibility to Rhizoctonia. However, in PeMV-tolerant Delray Bell, TMV-P and PeMV infections significantly increased susceptibility to Rhizoctonia, compared with single virus infections. TMV-Palone also increased susceptibility of Florida VR-2 to damping-off.

Keyword(s): Capsicum annuum.