VIEW ARTICLE

Physiology and Biochemistry

Replication and Properties of Cowpea Chlorotic Mottle Virus in Resistant Cowpeas. S. D. Wyatt, Department of Plant Pathology and Plant Genetics, University of Georgia, Athens, GA 30602, Present address of senior author: Department of Plant Pathology, Washington State University, Pullman, WA 99164; C. W. Kuhn, Department of Plant Pathology and Plant Genetics, University of Georgia, Athens, GA 30602. Phytopathology 69:125-129. Accepted for publication 21 August 1978. Copyright 1979 The American Phytopathological Society. DOI: 10.1094/Phyto-69-125.

Although cowpea chlorotic mottle virus (CCMV) caused no symptoms on cowpea PI 186465, virus could be isolated from the inoculated primary leaves but not from trifoliolate ones. Virus accumulation was continuous and linear in the primary leaves through a 52-day infection period. The average rate of accumulation (4.4 μg/g/24 hr) was 12 to 20 times less than the rate measured during the rapid phase of replication in susceptible California Blackeye cowpeas. Incorporation studies with ³²PO₄ suggested that CCMV RNA encapsidated late in the infection period came from a pool of RNA formed soon after inoculation. Several properties of CCMV produced in the resistant plants were similar to the inoculum (type strain): host range, serology, specific infectivity, and electrophoretic mobility. However, based on electrophoresis and buoyant density experiments, the RNA species 3 was reduced about 90% in virus purified from plants of PI 186465 in comparison to virus purified from California Blackeye. This alteration was not found in the RNA of progeny resulting from back inoculation to California Blackeye.