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ARS Home » Southeast Area » Tifton, Georgia » Crop Protection and Management Research » Research » Publications at this Location » Publication #134799
Title: LOST P1 ALLELE IN SH2 SWEET CORN: QUANTITATIVE EFFECTS OF P1 AND A1 GENES ON CONCENTRATIONS OF MAYSIN, APIMAYSIN, METHOXYMAYSIN, AND CHLOROGENIC ACID IN MAIZE SILK

Author
item Guo, Baozhu
item ZHANG, Z - UNIVERSITY OF GEORGIA
item BUTRON, A - PONTEVEDRA, SPAIN
item WIDSTROM, NEIL
item SNOOK, M - UNIVERSITY OF GEORGIA
item LYNCH, ROBERT
item PLAISTED, D - SYNGENTA SEEDS, INC.

Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/7/2004
Publication Date: 12/1/2004
Citation: Guo, B.Z., Zhang, Z.J., Butron, A., Widstrom, N.W., Snook, M.E., Lynch, R.E., Plaisted, D. 2004. Lost P1 allele in sh2 sweet corn: Quantitative effects of p1 and a1 genes on concentrations of maysin, apimaysin, methoxymaysin, and chlorogenic acid in maize silk. Journal of Economic Entomology. 97(6):2117-2126.

Interpretive Summary: Sweet corn is one of the highest ranking vegetable crops in the U.S. in terms of both market value and total acreage. Pesticides are also used intensively in the production of sweet corn due to consumer demand for zero damage to ears and to little or no resistance to ear feeding insects. As a result, growers in the South totally depend on scheduled pesticide applications to control ear-feeding insects with 25-40 applications of pesticide in a season. Field corn with resistance to the corn earworm has been identified due to antibiotic chemicals in the silks. We have been involved in a breeding program to transfer resistance to the corn earworm in sh2 sweet corn. In this study, we characterized the genetic markers controlling maysin, apimaysin, methoxymaysin, and chlorogenic acid in the silks. We demonstrated that a gene, P1, from the field corn, which was lost in the development of sweet corn, has a strong interaction with the a1 gene in sweet corn on the production of these chemicals. We developed markers for these two genes for use in breeding selection for individuals with homozygous recessive a1 from sweet corn and dominant P1 (from field corn), resulting in much higher antibiotic chemical compounds in the silks than the donor parental line. New sweet corn breeds of lines with the P1 gene may enhance sweet corn resistance to corn earworm, potentially reducing the number of insecticide applications required to produce sweet corn. Results of this study suggest that transferring the resistance may be an alternate strategy for control of corn earworm damage in sweet corn without the extensive use of pesticide.

Technical Abstract: In the U.S., pesticides are used intensively in the production of sweet corn due to consumer demand for zero damage to ears and to a genetic base in sweet corn with little or no resistance to ear feeding insects. As a result, growers in the South totally depend on scheduled pesticide applications to control ear-feeding insects with 25-40 applications of pesticide. We have been involved in a breeding program to transfer resistance to the corn earworm in sh2 sweet corn. In a study of quantitative genetic control over silk maysin, AM-maysin, and chlorogenic acid in an F2 population derived from GE37 (field corn, P1P1A1A1) and 565 (sh2 sweet corn, p1p1a1a1), we demonstrated that the P1 allele from the field corn, which was lost in the development of sweet corn, has a strong epistatic interaction with locus a1 on chromosome 3 in sh2 sweet corn. We detected that the p1 locus has significant effects (P < 0.0001) not only on silk maysin (61%) but also on AM-maysin (64.5%), and chlorogenic acid (12.5%). The a1 locus also has significant (P < 0,0005) effects on these silk antibiotic compounds. Breeding selection from selfed backcrosses for individuals with homozygous recessive a1 alleles (tightly linked to sh2 trait) and dominant P1 alleles (from field corn) have much higher (2 to 3 times) concentration of silk maysin and other compounds (AM-maysin and chlorogenic acid) than the donor parental line and may enhance sweet corn resistance to corn earworm, potentially reducing the number of applications required to produce sweet corn.