Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/10/1999
Publication Date: N/A
Interpretive Summary: Feeding by southwestern corn borer and fall armyworm larvae can damage the leaves, stalks, and ears of corn plants. Heavy damage to plants in the whorl stage of growth can result in substantial yield losses. Larval feeding damage to the ears provides potential sites for entrance of fungi that can further reduce yield and grain quality. Growing corn hybrids that have genetic resistance to insects is widely considered the best method of reducing damage to corn. To produce such hybrids, sources of insect resistance must be identified and developed. Mp713 and Mp714 were developed by several generations of selection for resistance to southwestern corn borer and fall armyworm. These two lines are now available to plant breeders with commercial seed 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: Two maize (Zea mays L.) germplasm lines designated Mp713 and Mp714 were released as sources 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 and Forestry Experiment Station in December 1998. Mp713 was developed from a cross between two S1 lines derived from Multiple Borer Resistant populations developed at the International Maize and Wheat Improvement Center in Mexico. Mp714 was developed from GT-DDSA (C5), a population developed and released by USDA-ARS and the University of Georgia Agricultural Experiment Station as a source of resistance to ear feeding by corn earworm (Helicoverpa zea). Mp713 and Mp714 were developed by self- pollinating plants for eight generations while selecting for resistance to southwestern corn borer and fall armyworm. Mp713, Mp714, Mp708 (resistant check), and Ab24E (susceptible check) were evaluated for resistance to leaf feeding by southwestern corn borer and fall armyworm in 1996, 1997, and 1998 by infesting plants in the whorl stage of growth with 30 neonate larvae and visually rating damage 14 d later on a scale of 0 (no damage) to 9 (extensive damage). When evaluated for resistance to southwestern corn borer, Mp713, Mp714, Mp708, and Ab24E rated 5.0, 5.6, 5.8, and 8.4, respectively. When evaluated for fall armyworm resistance, they rated 4.6, 5.5, 5.6, and 7.9, respectively. Mp713 and Mp714 are of medium height with Mp713 being slightly taller than Mp714. Mp713 has light yellow kernels and white cobs. Mp714 has white kernels and white cobs. Maturity classification for both lines is AES 1100.