Author
KIM, K - UNIV OF ILLINOIS | |
HILL, C - UNIV OF ILLINOIS | |
Hartman, Glen | |
Mian, Rouf | |
DIERS, B - UNIV OF ILLINOIS |
Submitted to: Crop Science
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 11/5/2007 Publication Date: 5/1/2008 Citation: Kim, K.S., Hill, C.B., Hartman, G.L., Mian, R.M., Diers, B.W. 2008. Discovery of Soybean Aphid Biotypes. Crop Science. 48(3):923-928. Interpretive Summary: The soybean aphid is an invasive insect pest of soybean that was first reported in North America in 2000. Soybean germplasm was screened for aphid resistance and several resistance sources have been identified. There are currently no reports of soybean aphid biotype diversity and this information is needed before aphid resistance genes are deployed. The objective of this research was to test for aphid biotype variation. All six aphid resistance sources provided resistance to the Illinois isolate, however, the Ohio isolate defeated the aphid resistance gene Rag1 from ‘Dowling’ and Rag from ‘Jackson’. PI200538 and PI567597C were resistant to both the Ohio and Illinois isolates and will be useful sources of resistance to both isolates. These results are the first to confirm that there are at least two distinct biotypes of A. glycines in North America. This manuscript is highly relevant to scientists involved in improving soybean productivity. Technical Abstract: The soybean aphid [Aphis glycines Matsumura (Hemiptera: Aphididae)] is an invasive insect pest of soybean [Glycine max (L.) Merr.] that was first reported in North America in 2000. Soybean germplasm was screened for aphid resistance and several resistance sources have been identified. There are currently no reports of soybean aphid biotype diversity and this information is needed before aphid resistance genes are deployed. The objective of this research was to test for aphid biotype variation. The response of two A. glycines isolates, one collected in Ohio and the other in Illinois, were compared by infesting eight soybean genotypes, six previously found to be resistant, in nonchoice tests. The same genotypes also were tested with the Ohio isolate using a choice test. In the nonchoice test, there was a significant (P<0.0001) effect of aphid isolate, genotype, and a significant aphid isolate by soybean genotype interaction for the number of aphids per plant 10 and 15 days after infestation. In this nonchoice test, all six resistance sources provided resistance to the Illinois isolate, however, the Ohio isolate defeated the aphid resistance gene Rag1 from ‘Dowling’ and Rag from ‘Jackson’. PI200538 and PI567597C were resistant to both the Ohio and Illinois isolates and will be useful sources of resistance to both isolates. The responses of the eight genotypes to the Ohio isolate in the choice test were similar to their responses in nonchoice tests. These tests confirm that there are at least two distinct biotypes of A. glycines in North America. |