Genetics. Published Articles Ahead of Print: March 4, 2007, Copyright © 2007
doi:10.1534/genetics.106.067892


A more recent version of this article appeared on May 1, 2007.

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Precise mapping of Quantitative Trait Loci for Resistance to Southern Leaf Blight, caused by Cochliobolus heterostrophus race O, using an Advanced Intercross Maize Population

Peter Balint-Kurti 1*, John C Zwonitzer 2, Randall J Wisser 2, Martin Carson 3, Marco A. Oropeza-Rosas 2, James B Holland 4 and Steven J Szalma 2

1 USDA-ARS, North Carolina State University
2 North Carolina State University
3 USDA-ARS, Cereal Disease Laboratory
4 USDA-ARS

* To whom correspondence should be addressed. E-mail: peter_balintkurti{at}ncsu.edu.

Submitted on November 6, 2006
Revised on January 2, 2007
Accepted on 21 February 2007


Abstract

The IBM population, an advanced intercross recombinant inbred line population derived from a cross between the maize lines B73 (susceptible) and Mo17 (resistant), was evaluated in four environments for resistance to southern leaf blight (SLB) disease caused by Cochliobolus heterostrophus race O. Two environments were artificially inoculated, while two were not inoculated and consequently had substantially lower disease pressure. Four common SLB resistance QTL were identified in all environments; two in bin 3.04 and one each in bins 1.10 and 8.02/3. There was no significant correlation between disease resistance and days to anthesis. A direct comparison was made between SLB QTL detected in two populations, independently derived from the same parental cross; the IBM advanced intercross population and a conventional recombinant inbred line population. Several QTL for SLB resistance were detected in both populations, with the IBM providing between five and, in one case, fifty times greater mapping resolution.

Key Words: Advanced intercross population, Disease resistance, Plant Disease, Quantitative Trait Loci