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.