Relation of Verital Root-Pull Resistance and Flowering in Maize
1983
Interest in development of maize (Zea mays L.) roots has increased the past 20 years because of the incidence of maize rootworms (Diabrotica species) in the U.S. Corn Belt. Objectives of our study were to determine whether preflower root-pull resistance was related to postflower root-pull resistance and whether preflower root-pull resistance should be included in recurrent selection programs to enhance resistance to root lodging. We evaluated 98 Sj progenies derived from each of four populations at two locations for 3 years for rootpull resistance and at one location for 3 years for frequency of root lodging. The S, progeny heritability estimates for pre- (76%) and postflower (81%) root-pull resistance and root lodging (74%) were relatively high, suggesting that progress could be made for each trait. Genetic correlations between pre- and postflower root-pull resistance ranged from 0.78 to 0.90, but the average genetic correlations between preflower (r = − 0.20) and postflower (r = −0.28) root-pull resistance and percentage of root lodging were relatively low. Predicted correlated response of postflower root-pull resistance based on preflower root-pull resistance was 81.3% (23.9 kg) of predicted direct response (29.4 kg) for postflower root-pull resistance. Though correlated responses of root-pull resistance for resistance to root lodging were only 35.5% (postflower) and 25.8% (preflower), greater resistance to root pulling would contribute to reduced root lodging. Our results suggest preflower root-pull resistance was a good predictor of postflower rootpull resistance and that effective selection can be made at flowering for increased root-pull resistance.
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