Development of Heterodera glycines pathotypes as affected by soybean cultivars.

The reproductive abilities of four races of Heterodera glycines were compared on soybean cultivars by using single cyst or mass inoculations. Progeny transfers were used to determine changes in reproduction of H. glycines. Reproduction of all races (1, 2, 3, 4) was best on 'Lee' and poorest on P1 88788. The size of females produced and numbers of eggs/female of the different races varied with the cultivar. Races 1 and 3 appeared to contain low populations of Races 2 or 4. Races 2 and 4 were best selected by a series of transfers on 'Pickett' soybean.