Biotypic variation among soybean aphid isolates from four provinces in China

The soybean aphid [Aphis glycines Matsumura (Hemiptera: Aphididae)] is an important pest insect of soybean [Glycine max (L.) Merr.] in China and North America. Identification of soybean aphid biotypes would facilitate more effective pest management. Although four soybean aphid biotypes have been discovered in North America to date, biotype determination has not been conducted in China. In this study, we analyzed the biotypes of soybean aphids collected from four different soybean-growing areas in China in 2011. The responses of four soybean aphid isolates from Changchun (Jilin province), Jinan (Shandong province), and Shanghai and Guiyang (Guizhou province) were assessed by infesting 11 soybean genotypes in noncaged tests during 2 yr and infesting 7 genotypes in a caged test in 1 yr. We distinguished among the four isolates on the basis of their abilities to infest a set of host plants with the known resistance genes Rag1 through Rag6. The results showed that the bio-type profiles of the four soybean aphid isolates were different from each other and that there are at least four biotypes of soybean aphid in China.