Sugarcane Mosaic Virus Strain Maize Dwarf Mosaic Virus B as a Pathogen of Eastern Gamagrass. D. L. Seifers, Associate Professor, Fort Hays Branch Agricultural Experiment Station, Hays, KS 67601-9228. M. K. Handley, and R. L. Bowden. Plant Pathologist, The Land Institute, Salina, KS 67401; and Assistant Professor, Plant Pathology Department, Kansas State University, Manhattan 66506. Plant Dis. 77:335-339. Accepted for publication 20 November 1992. Copyright 1993 The American Phytopathological Society. DOI: 10.1094/PD-77-0335.

Eastern gamagrass (EGG) (Tripsacum dactyloides) is a high-quality, high-production native forage grass with potential as a high-protein, perennial grain crop. We used enzyme-linked immunosorbent assay to test EGG samples for virus infection. Over a 2-yr period, we found five instances of maize dwarf mosaic virus (MDMV) and a high incidence (12 and 72% in 3-mo-old and 5-yr-old plantings, respectively) of sugarcane mosaic virus strain MDMV-B (SCMV-MDMV-B) in experimental breeding nurseries in Kansas. Incidence of SCMV-MDMV-B was higher in older breeding nurseries. SCMV-MDMV-B, but not MDMV, was found in three of 42 natural EGG stands. EGG plants infected by SCMV-MDMV-B showed no symptoms or a range of symptoms from mild mosaic to extensive chlorotic spots that became necrotic. EGG seedlings grown from two seed sources and inoculated in the greenhouse were infected by four MDMV and five SCMV-MDMV-B isolates. SCMV-MDMV-B apparently overwinters in infected EGG and has the potential to be a serious disease problem for this crop.