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Ecology and Epidemiology

Susceptibility of Representative Native Mississippi Grasses in Six Subfamilies to Maize Dwarf Mosaic Virus Strains A and B and Sugarcane Mosaic Virus Strain B . Eugen Rosenkranz, Research plant pathologist, Agricultural Research Service, U.S. Department of Agriculture and professor, Department of Plant Pathology and Weed Science, Mississippi State University, Mississippi State 39762; Phytopathology 73:1314-1321. Accepted for publication 11 April 1983. 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, 1983. DOI: 10.1094/Phyto-73-1314.

A representative collection of the Mississippi grass flora, consisting of 42 annual and 71 perennial grasses, contained 79 host species and 34 nonhost species of maize dwarf virus strain A (MDMV-A), strain B (MDMV-B), and sugarcane mosaic virus strain B (SCMV-B). Of the 79 host species, 68 were new hosts which were divided into 63 species susceptible to MDMV-A, 47 species susceptible to MDMV-B, and 48 species susceptible to SCMV-B; 40 species were susceptible to all three strains. Among the 34 insusceptible species, 29 were new nonhosts. Host species were found in all six subfamilies of the Gramineae, in 14 of 16 tribes, and in 40 of 51 genera included in this study. The subfamily Festucoideae had the highest percentage of species with latent infection, and the festucoid species also exhibited the least differential reaction to the three virus strains. The tribe Andropogoneae in the subfamily Panicoideae had the highest proportion of hosts to nonhosts, but species with the greatest susceptibility were in the tribe Paniceae. The subfamily Eragrostoideae had twice as many species susceptible to MDMV-A as to MDMV-B or SCMV-B. Of the two Mississippi species in the subfamily Bambusoideae, one was latently susceptible to MDMV-A, the other insusceptible to all three strains. Eight of the nine species in the subfamily Oryzoideae occurring in Mississippi were hosts of MDMV or SCMV. Species in the subfamily Arundinoideae were evenly divided between hosts and nonhosts. Host species made up 88% of the annual and 61% of the perennial grasses tested. Infectivity profile of MDMV-B resembled more closely that of SCMV-B than that of MDMV-A. Genera with the closest taxonomic position to corn seem less susceptible to these viruses than genera somewhat more distant to corn in the phylogeny of the Gramineae.