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United States Department of Agriculture

Agricultural Research Service


item Mcmullen, Michael
item Lee, Elizabeth
item Snook, Maurice
item Musket, Theresa
item Guill, Katherine - Kate
item Byrne, Patrick
item Coe Jr, Edward

Submitted to: Maize Genetics Conference Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 3/23/1998
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: The accumulation of maysin, a C-glycosyl flavone in maize silk, is an important component of antibiosis to the corn earworm. We have previously demonstrated the importance of the p1 locus as a quantitative trait locus (QTL) for maysin synthesis. We have also identified a locus on chromosome 9S, designated rem1, that has large effects on maysin levels. The rem1 effect requires a functional p1 allele, and rem1 exhibits a highly significant epistatic interaction with alleles of the p1 locus. We have proposed that the rem1 effect involves an interconnecting pathway with flavone synthesis. To directly test the importance of genes in interconnected pathways as QTLs for maysin synthesis, we have developed a (W23a1 x GT119) F2 population. W23a1 has a functional p1-wrb allele, but has the recessive, non-functional a1 allele. GT119 has a nonfunctional p1-www allele and a functional a1 allele. The a1 locus is not required for the synthesis of flavones, but is required for the synthesis of 3-deoxyanthocyanins in maize silks. Results of analysis of maysin levels in the silks of 226 F2 plants reconfirmed the importance of the p1 locus (P<0.0001). The a1 locus was also highly significant (P<0.0001) as was the p1 x a1 epistatic interaction (P<0.0001). A multiple locus model including p1, a1 and the p1 x a1 interaction accounts for 68% of the phenotypic variance for maysin levels. These results indicate that shunting of biochemical intermediates between pathways can be the biological basis of major QTLs for agronomic traits.

Last Modified: 10/17/2017
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