|Davis, Frank - RETIRED ARS|
Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: August 31, 2001
Publication Date: March 20, 2002
Interpretive Summary: Feeding by southwestern corn borer and fall armyworm larvae damages leaves, stalks, and ears of corn plants and can substantially reduce grain yields. Larval feeding on the ears provides potential sites for entrance of fungi that can further reduce yield and grain quality. Growing hybrids with genetic resistance to insects is widely considered the best method of reducing these losses. To produce such hybrids, germplasm with resistance to insects must first be identified and developed. Mp716 was developed by several generations of breeding and selection for resistance to southwestern corn borer and fall armyworm. It has consistently exhibited a good level of resistance to both insects. This line is now available to plant breeders with commercial seed corn companies and can be used in developing corn hybrids with resistance to these insects. When farmers grow these hybrids, insect damage will be reduced.
Technical Abstract: Maize (Zea mays L.) germplasm line, Mp716, was released as a source of resistance to leaf feeding by southwestern corn borer, Diatraea grandiosella Dyar, and fall armyworm, Spodoptera frugiperda (J. E. Smith), by USDA-ARS and the Mississippi Agricultural Experiment Station in January 2001. Mp716 was derived from a cross between Mp708 and Mp78: 518, an unreleased line derived from Antiqua Group 2 and Dominican Republic Group 1. Mp716 was developed by breeding and selecting for resistance to southwestern corn borer and fall armyworm for eight generations. Mp716 was evaluated for resistance to southwestern corn borer and fall armyworm in replicated field trials in 1998, 1999, and 2000. Plants in the whorl stage of growth were infested with 30 neonate larvae, and damage was visually rated 14 days later on a scale of 0 (no damage) to 9 (heavy damage). When evaluated for resistance to southwestern corn borer, Mp716 rated 5.2; resistant check Mp708, 6.1; and susceptible check Tx601, 8.7. Fall armyworm damage ratings were 4.9, 5.7, and 8.4, respectively. Mp716 plants are approximately 2 meters tall. Kernels are yellow, and cobs are white.