Submitted to: Maize Genetics Conference Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 3/22/1998
Publication Date: N/A
Citation: N/A Interpretive Summary:
Technical Abstract: European corn borer (Ostrinia nubilalis Hubner) is a serious insect pest of maize (Zea mays L.) in the United States. The objectives of this study were to (1) determine the number and the genomic positions of quantitative trait loci (QTL) conferring resistance to the first- and second-generation of European corn borer (1ECB, 2ECB), and (2) determine the size and type of their genetic effects. Two hundred forty-four F3 families derived from the cross of B73 (susceptible) x Mo47 (resistant) were genotyped at 99 RFLP and three SSR marker loci. For evaluating resistance against 1ECB, plants were manually infested with 160 neonate ECB larvae placed into the plant whorl at the six-to-eight-leaf stage (mid-whorl). Leaf feeding damage was assessed three weeks after infestation with a visual rating scale. Evaluation for resistance to 2ECB involved manual infestation at anthesis by placing 160 neonate ECB larvae in the leaf axil at the ear node and/or just above and below the node. Approximately seven weeks later, stalks were split lengthwise and the length of ECB tunnels was visually estimated. Phenotypic data were analyzed using proprietary FORTRAN software, the linkage and order of markers were determined by using MAPMAKER/EXP. In the combined analysis across three locations, composite interval mapping by QTL Cartographer identified resistance against 1ECB on chromosomes 1C, 1L, 2L, 4S, 4L, 5L, 6S, and 8L. Quantitative trait loci for 2ECB were found on chromsomes 2S, 3L, 5L, 6S, 6L, and 9S. The phenotypic variance expalined by the best multilocus model was 58.2% for 1ECB and 50.6% for 2ECB.