Identification of Soybean Resources of Resistance to Aphids

Four soybean [Glycine max (L.) Merr.] cultivars with soybean aphid resistance (Aphis glycines Matsmura), P189, P203, P574, and P746, were identified in field test, choice test, and non-choice test. The grade of resistance to aphids and the damage index of P189, P203, and P746 were significantly different from the susceptible cultivars (P = 0.05). P574 and P746 showed antibiosis resistance, preventing aphids from reproducing on the plants. P203 showed antixenosis resistance, preventing aphids from reproducing in field test and choice test, but susceptible in non-choice test. Population development on plants was significantly different in field test, choice test, and non-choice test, which was caused by different selective pressures.