VIEW ARTICLE

Resistance

Effects of Genotype and Inoculation Protocols on Resistance Evaluation of Maize to Maize Dwarf Mosaic Virus Strains. Raymond Louie, Research plant pathologist, Agricultural Research Service, U.S. Department of Agriculture, The Ohio State University, Ohio Agricultural Research and Development Center, Wooster 44691; Phytopathology 76:769-773. Accepted for publication 26 February 1986. This article is in the public domain and not copyrightable. It may be freely reprinted with customary crediting of the source. The American Phytopathological Society, 1986. DOI: 10.1094/Phyto-76-769.

Responses of maize inbreds A239, A375, B14, CG1, C1.44, Ky61:2335, Ky66:2500, Oh28, M14, Pa32, Pa405, and Va35 to inoculation protocols with maize dwarf mosaic virus (MDMV) strains A and B were determined. Protocols included age of test plant at inoculation, number of repeated inoculations per plant, number of rubs per inoculation, and inoculum dilutions. Tests involving four inoculations with two rubs at 4-day intervals resulted in the greatest number of infected plants in all inbreds. Except for the number of repeated rub inoculations per plant with MDMV-A, cluster analysis of area under the disease progress curve separated inbreds into more groupings than did cluster analysis of final readings. MDMV-B was generally not more virulent than MDMV-A except in the number of repeated rub-inoculation tests involving inbreds A239, B14, M14, and Va35. Inbred Pa405 was most resistant to both strains. The significance of variation in host response to different inoculation protocols in studies of disease resistance evaluation is discussed.