Submitted to: Annual Meeting Central States Entomological Society
Publication Type: Abstract Only
Publication Acceptance Date: March 27, 1995
Publication Date: N/A
Technical Abstract: The western corn rootworm is among the most important insect pests in the United States, yet no lines of corn have been previously found with antibiosis resistance to corn rootworm larvae. We are conducting field, greenhouse, and laboratory screening of exotic maize and maize relatives in an effort to identify germplasm resistant (antibiosis/nonpreference) to this pest. In 1994, we evaluated more than 600 accessions of maize and maize relatives for resistance to corn rootworms in artificially-infested field trials. As indicated by root damage ratings, considerable variation in susceptibility to rootworm attack existed between the accessions. More than 100 of the 1994 accessions had been selected from similar field trials in both 1992 and 1993 (selections based upon root damage ratings). We selected 28 of these accessions to be advanced to a second cycle of selection. In addition, 118 accessions were selected for further evaluation from our primary screen of new exotic germplasm. Forty accessions were chosen for replicated trials in 1994. The best three accessions had significantly lower root ratings than the worst five accessions, but were better than our "susceptible" controls. Tripsacum-introgressed maize was evaluated for corn rootworm resistance in the field for the first time in 1994. Root damage ratings were quite variable, and we selected 12 of 48 accessions to form our first cycle of selection. Laboratory bioassays involving host plant recognition are under way and may provide an additional tool for evaluating germplasm. Our project involves entomologists, a corn breeder, and corn geneticists. Preliminary data make us optimistic about our chances of finding germplasm with antibiosis toward corn rootworms.