Submitted to: Phytopathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/30/2007
Publication Date: 3/12/2008
Citation: Balint Kurti, P.J., Zwonitzer, J., Wisser, R., Pe, E., Pea, G., Lee, M., Cardinal, A. 2008. Identification of Quantitative Trait Loci for Resistance to Southern Leaf Blight and Days to Anthesis in Two Maize Recombinant Inbred Line Populations. Phytopathology. 98:315-320. Interpretive Summary: We have identified regions of the genome that confer resistance to southern leaf blight in two different populations. Comparing these regions to other regions reported previously we can identify ‘hot-spots’ for southern leaf blight disease resistance genes in the genome. We also provide evidence that in some cases southern leaf blight resistance may be due to components of the plant cell wall.
Technical Abstract: Two recombinant inbred line populations derived from crosses between maize lines H99 and B73 (HB population) and between B73 and B52 (BB population) were evaluated for resistance to southern leaf blight (SLB) disease caused by Cochliobolus heterostrophus race O and for days to anthesis (DTA) in two environments. Entry mean heritabilities for disease resistance were high for both populations (0.876 and 0.761 respectively). Quantitative trait loci (QTL) for SLB resistance were identified in bins 3.04 (two QTL), 6.01 and 8.05 in the HB population and in bin 2.07 in the BB population. No overlap of DTA and SLB resistance QTL was observed, nor was there any phenotypic correlation between the traits. A comparison of the results of all published SLB resistance QTL studies suggested that bins 3.04 and 6.01 are ‘hotspots’ for SLB resistance QTL. The co-localization of QTL for SLB resistance and cell wall components in the BB population was also noted. The significance of this co-localization is not clear but it suggests that the cell wall may play a role in SLB resistance.