Combining Ability for Resistance in Corn To Fall Armyworm and Southwestern Corn Borer
- W. Paul Williams ,
- Paul M. Buckley and
- Frank M. Davis
Both the fall army worm, Spodoptera frugiperda (J.E. Smith), and the southwestern corn borer, Diatraea grandiosella Dyar, feed extensively on the leaves of corn, Zea mays L., in the southern USA. Their feeding can cause serious yield reductions. Several germplasm lines with resistance to leaf feeding by these two insect pests have been developed and released; however, only limited information is available on the inheritance of this resistance. No previous information on the relationships between resistance to fall armyworm and southwestern corn borer has been reported. The current investigation was undertaken to obtain information on the relative importance of general and specific combining ability in the inheritance of resistance to fall armyworms and southwestern corn borers and to compare the responses of the two insects to a diallel cross among inbred lines with varying degrees of resistance. Larval survival and growth were used to quantify levels of resistance. General combining ability was a highly significant source of variation among hybrids, but specific combining ability was a nonsignificant source of variation. Fall armyworm larval survival and weight on hybrids with varying levels of resistance were highly correlated with southwestern corn borer survival and weight on the same hybrids. This suggests that selecting for resistance to one of these insects should increase resistance to both.
Copyright © 1989.