Submitted to: Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: July 21, 2000
Publication Date: N/A
Technical Abstract: Southwestern corn borer, Diatraea grandiosella Dyar, is a major insect pest of maize, Zea mays L., in the southern USA. When plants are attacked during the vegetative stage of plant development, larvae feed initially on leaves within the plant whorl. After anthesis, larvae feed on husks and kernels of developing ears before tunneling into the stalk. Larval feeding on the ears provides entrance to fungi. One such fungus is Aspergillus flavus Link: Fr. This fungus produces aflatoxin, a potent carcinogen. Aflatoxin contamination reduces the value of the grain, or even renders it unmarketable. Little is currently known about the association between southwestern corn borer damage and aflatoxin accumulation. This investigation was undertaken to compare aflatoxin accumulation in crosses among maize inbred lines with different levels of southwestern corn borer resistance in an eight-parent diallel cross. General combining ability was a highly significant source of variation in the inheritance of resistance to stalk tunneling and ear damage by southwestern corn borer. Both stalk tunneling and ear damage were lowest in crosses with the inbred line Mp496 as a parent. General combining ability was also a significant source of variation in the inheritance of resistance to aflatoxin accumulation.