|Holland, Jim - Jim|
Submitted to: Crop Science
Publication Type: Peer reviewed journal
Publication Acceptance Date: 3/5/2007
Publication Date: 9/15/2007
Citation: Holland, J.B., Roberston-Hoyt, L.A., Kleinschmidt, C.E., White, D.G., Payne, G.A., Maragos, C.M. 2007. Relationships of resistance to Furarium ear rot and fumonisin contamination with agronomic performance of maize. Crop Science. 47(5):1770-1778. Interpretive Summary: Fusarium ear rot is a serious disease of corn, particularly in southeastern USA. The fungi that cause this disease also can produce a mycotoxin, called fumonisin, that is harmful to human and animal health. Breeding for corn with high levels of resistance to Fusarium ear rot and resistance to contamination by mycotoxin can minimize yield losses and health effects of this disease. We have mapped genes for resistance to this disease in one population, and we can use this population to incorporate resistance genes from the highly resistant donor line, GE440, to the susceptible but commercially successful recurrent parent line, FR1064. This experiment investigated the relationship between disease resistance and agronomic utility in this population to allow prediction of the effect of breeding for disease resistance on yield and agronomic performance. Our gene mapping results suggest that only a small reduction in grain yield and a small increase in plant height would result from backcrossing the resistance genes into FR1064.
Technical Abstract: Resistance to Fusarium ear rot and fumonisin contamination is heritable and controlled by at least 11 gene regions in a maize population created by backcrossing the highly resistant donor line, GE440, to the susceptible but commercially successful recurrent parent line, FR1064. To investigate the relationship between disease resistance and agronomic utility in this population, resistances to Fusarium ear rot and fumonisin contamination were measured in BC1F1:2 lines, and yield and agronomic performance were measured in topcrosses of these lines. Fumonisin contamination was not correlated with yield, but two fumonisin QTLs mapped to similar positions as yield QTLs. In contrast, Fusarium ear rot was positively correlated with topcross yield (r = 0.29), but QTLs for the two traits mapped to distinct genomic positions. Similar results for other traits indicate that QTLs can contribute in opposite directions to the overall genetic correlations between traits, and that some trait correlations arise in the absence of detectable QTL effects on both traits. If backcrossing were utilized to introgress fumonisin contamination resistance alleles into the FR1064 background, correlation results suggest that the resulting lines would have increased grain moisture and decreased stalk lodging relative to FR1064. Our QTL mapping results suggest that only a small reduction in grain yield and a small increase in plant height would result.