Submitted to: Maize Genetics Conference Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: January 31, 2003
Publication Date: March 15, 2003
Citation: Jones, M.W., Louie, R., Redinbaugh, M.G., Todd, J.C. 2003. Searching for virus resistance genes - is mdm1 a universal virus resistance gene?. Maize Genetics Conference Abstracts. p. 188. Technical Abstract: Previously, a gene controlling resistance to Maize dwarf mosaic virus strain A (MDMV) was identified in the inbred line Pa405. The gene was closely linked to the RFLP marker umc85 on the short arm of chromosome 6. This gene also conferred resistance to two other viruses in the family Potyviridae: Sugarcane mosaic virus (SCMV/MDM-B) and Wheat streak mosaic virus (WSMV). To determine whether resistance to these viruses was linked to the gene on chromosome 6S in a diverse array of maize germplasm, we identified 42 MDMV-resistant inbred lines, then crossed these lines to three MDMV susceptible inbreds and developed F2 populations. The F2 populations were screened with MDMV and leaf tissue from susceptible and resistant pools was screened with RFLP and SSR markers. In 40 of the 42 inbreds, chromosome 6S markers associated with the resistant parent were found in the resistant, but not the susceptible pooled tissue. In addition, markers associated with SCMV/MDM-B was WSMV resistance on chromosome 3 and WSMV resistance on chromosome 10 were found only in the pooled resistant tissue for 12 and 7 inbreds, respectively. These data suggest that mdml is associated with MDMV resistance in most germplasm, but that other loci may also affect resistance. In addition to resistance genes, rating date and environmental factors influenced the development of symptoms and subsequent phenotypic ratings. Because of this, it was not possible to determine the type of gene action.