Submitted to: Aflatoxin Elimination Workshop Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 12/31/2001
Publication Date: 3/1/2002
Citation: Guo, B., Xu, G., Cao, Y.G., Widstrom, N.W., Lynch, R.E. 2002. RFLP markers associated with silk antibiosis and PCR-based markers for marker-assisted selection [abstract]. Mycopathologia. 155:89. Interpretive Summary:
Technical Abstract: Maysin, a C-glycosylflavone in maize silk, has insecticidal activity against corn earworm (Helicoverpa zea Boddie) larvae. Sweet corn (Zea mays L.) is a vulnerable crop to ear-feeding insects and requires pesticide protection from ear damage. This study was conducted to identify maize chromosome regions associated with silk maysin concentration and eventually to transfer and develop high silk maysin sweet corn lines with marker-assisted selection (MAS). Using F2 population derived from dent corn (high maysin) and sweet corn (low maysin sh2), we detected two major quantitative trait loci (QTL), p1 on chromosome 1S and a1 on chromosome 3L. Locus a1 has a recessive gene action for high maysin with the presence of functional p1 allele. A multiple-locus model, which included p1, a1, and the epistatic interactions p1 x a1 accounted for 76.3% of the total silk maysin variance. Tester crosses showed that, at the a1 locus, dent corn has functional A1 alleles and sh2 sweet corn has homozygous recessive a1 alleles. Individuals of BC1 were examined with MAS and plants with p1 allele from dent and homozygous a1 alleles from sweet corn had consistent high silk maysin. Marker-assisted selection seems to be a suitable method to transfer silk maysin in these lines. For the practical application in marker-assisted selection, we have generated PCR- based markers from RFLP markers.