Reproduction of the reniform nematode on thirty soybean cultivars

In greenhouse experiments conducted in 1991 and 1992, the 30 soybean (Glycine max) cultivars most commonly grown in Arkansas in 1990 were tested for resistance to the reniform nematode, Rotylenchulus reniformis. 'Forrest' was the most resistant cultivar, whereas 'Braxton' was the most susceptible to R. reniformis. Cultivars Coker 485, Centennial, Stonewall, and Sharkey did not differ from Forrest (P = 0.01). Cultivars Lee 74, Coker 6955, Waiters, Davis, Pioneer 9442, and Narow did not differ from Braxton (P = 0.01). Cultivar Lloyd had the second highest reproductive index (Pf/Pi) in 1992 and for the combined test, but was significantly different from Braxton in 1991. The remaining cultivars were inconsistent in their reproductive indices. Two cultivars, Leflore and Lloyd, exhibited large variation in Pf/Pi. This may be due to multiple resistance genes and (or) segregation for resistance among individual seedlings. Segregation is possible because these varieties were not selected or tested for reniform nematode resistance during the cultivar development process.