Submitted to: ASA-CSSA-SSSA Annual Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: November 3, 2003
Publication Date: November 3, 2003
Citation: Willmot, D.B., Elder, J.M., Hibbard, B.E. 2003. Mapping genomic regions associated with corn rootworm resistance [abstract]. ASA-CSSA-SSSA Annual Meeting. Paper No. C07-Willmot331082-Poster. Technical Abstract: Corn rootworms (Diabrotica spp.) (CRW) are the most costly agricultural pests in the United States. Recently, resistant transgenic corn hybrids have been released, but significant native plant resistance has not been commercialized. Selective genotyping with molecular markers has been employed for other simple and multigenic traits to identify major genes and chromosomal regions with intermediate effects. We have developed two related populations from domestic and exotic sources that segregate widely for CRW resistance and susceptibility. From an initial set of 400 families, four cycles of field and greenhouse selection under artificial infestation were conducted. From these, 19 consistently resistant and 17 susceptible S2 families were identified for this study. These 'tails' of the distribution are about two standard deviations apart for root feeding damage. Microsatellite markers were run on agarose gels (53) or on an ABI 3100 capillary electrophoresis genetic analyzer (121). Extra coverage was given to regions containing such candidate genes as bx1, aquaporins, chitinase A1, cyclin, actin, and beta glucosidase. Chi-square analysis will be performed for each marker to detect divergence from Hardy-Weinberg equilibrium within each of the tails. Results from a smaller set of SNP and MITEs markers will also be presented.