A Physalis Species More Sensitive than P. pubescens as an Indicator Plant for Potato Leafroll Virus. J. A. C. de Souza-Dias, Seção de Virologia, Instituto Agronômico, Cx. Postal 28, CEP 13001, Campinas-SP, Brazil. A. S. Costa, Seção de Virologia, Instituto Agronômico, Cx. Postal 28, CEP 13001, Campinas-SP, Brazil. Plant Dis. 75:101. Accepted for publication 12 July 1990. Copyright 1991 The American Phytopathological Society. DOI: 10.1094/PD-75-0101A.
For over 35 yr, potato leafroll virus (PLRV) has been identified at the Department of Plant Virology, Instituto Agronomico, using a species of Physalis L. (1) close to P. heterophylla Nees and more sensitive than the standard P. pubescens L. (= P. floridana Rydb.) to PLR V infection. After inoculation, this species, collected at Campinas-SP, Brazil, shows earlier and more defined symptoms of PLRV infection than P. pubescens. Stunting, interveinal chlorosis, and epinasty become evident within 8-12 days after inoculation, then intensify. On P. pubescens, symptoms appear 2-4 days later and are milder. Virus concentration is comparable in both species of Physalis when determined serologically (ELISA). Our species of Physalis has outperformed P. pubescens in tests done with Brazilian isolates of PLRV in Brazil and with U.S: isolates in Wisconsin. The excellent performance of this species as an indicator plant for PLRV was also observed by A. B. R. Beemster (personal communication) in assays performed at IPO in Wageningen, Netherlands. Seeds of the new Physalis indicator plant may be obtained from the authors.