Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/21/1997
Publication Date: N/A
Citation: Interpretive Summary: Over twenty-five years ago the first insect resistant introductions were identified in the USDA Soybean Germplasm Collection. These accessions have been used to develop insect resistant cultivars. No new sources of resistance have been found since then and significant insect damage can occur on the cultivars developed from these sources. More than 700 accessions recently obtained from China were screened for resistance to Mexican bean beetle and five accessions were identified that had useable levels of resistance. The level of resistance in these accessions was not as high as in previously identified sources but the new sources of resistance come from central China whereas the previous sources came from southern Japan. Because of the large differences in time of maturity and origin, it is likely that the sources of resistance from China could contain genes for insect resistance not found in the accessions from Japan. Combining the two sources of resistance may provide greater protection against insect feeding than has been previously achieved. Breeders and entomologists will use the results of this research as they strive to develop insect resistant cultivars.
Technical Abstract: Breeders and entomologists have continued to search for new sources of insect resistance in soybeans, Glycine max (L.) Merrill, because of the narrow genetic base currently in use in the development of insect-resistant soybeans. Recently, many new soybean accessions from China have been obtained. Ohio and Illinois concurrently examined these lines belonging to maturity groups I through IV for insect resistance using the Mexican bean beetle, Epilachna varivestis Mulsant, (in both states) and the potato leafhopper, Emposasca fabae Harris (in Illinois). Several introductions (PI 567.452, PI 567.685, PI 567.751C, PI 567.765D, and PI 567.770C) have potentially useable levels of resistance. Although none of these accessions had resistance levels as high as the earlier described lines of PI 171.451, PI 229.358, and PI 227.687, the new sources of resistance have a very different origin and are much earlier in maturity and may have different genes for resistance.