|ZAMBRANO, JOSE - The Ohio State University|
|FRANCIS, DAVID - The Ohio State University|
|Redinbaugh, Margaret - Peg|
Submitted to: Plant Disease
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/29/2013
Publication Date: 11/1/2013
Publication URL: http://handle.nal.usda.gov/10113/59719
Citation: Zambrano, J.L., Francis, D.M., Redinbaugh, M.G. 2013. Identification of resistance to Maize rayado fino virus in maize inbred lines. Plant Disease. 97(11):1418-1423.
Interpretive Summary: Viruses and other insect transmitted diseases cause significant losses in crops, including corn, world-wide. Controlling these diseases with virus-resistant cultivars and hybrids is both economically viable and environmentally sustainable. However, suitable virus-resistant plant materials must first be identified. Maize rayado fino (maize fine stripe) can cause large losses for producers in Central and South America, but maize lines with strong resistance to Maize rayado fino virus (MRFV), the pathogen causing the disease were not known. We screened 36 lines for resistance to MRFV, taking advantage of a set of lines (the Nested Association Mapping Population) developed by ARS and university researchers that represent 67% of the genetic diversity in corn. We found three lines with very strong resistance to MRFV, and another two lines with moderate resistance to infection by the virus. Resistance conferred by one of the lines, Oh1VI, appears to be controlled by one or two genes. The discovery of novel sources of resistance in corn will facilitate the identification and mapping of genes for MRFV resistance and will help breeders develop cultivars and hybrids resistant to this disease.
Technical Abstract: Maize rayado fino virus (MRFV) is one of the most important virus diseases of maize in America. Severe yield losses, ranging from 10 to 50% in landraces to nearly 100% in contemporary cultivars, have been reported. Resistance has been reported in populations, but few inbred lines have been identified with resistance. Maize inbred lines representing the range of diversity in the cultivated types and selected lines known to be resistant to other viruses were evaluated to identify novel sources of resistance to MRFV. Virus was transmitted using the vector Dalbulus maidis, and disease incidence and severity were evaluated beginning seven days post inoculation. Most of the 36 lines tested were susceptible to MRFV, with mean disease incidence ranging from 21 to 96%, and severity from 1.0 to 4.3 (using a 0 to 5 severity scale). A few genotypes, including CML333 and Ki11, showed intermediate levels of resistance, with 14% and 10% incidence, respectively. Novel sources of resistance, with incidence of less than 5% and severity ratings of 0.4 or less, included the inbred lines Oh1VI, CML287, and Cuba. Resistance carried by Oh1VI was dominant, and F2 segregation was consistent with one or two resistance genes. The discovery of novel sources of resistance in maize inbred lines will facilitate the identification of virus resistance genes and their incorporation into breeding programs.