Theoretical and Applied Genetics

, Volume 118, Issue 5, pp 911–925

Use of selection with recurrent backcrossing and QTL mapping to identify loci contributing to southern leaf blight resistance in a highly resistant maize line

  • John C. Zwonitzer
  • David M. Bubeck
  • Dinakar Bhattramakki
  • Major M. Goodman
  • Consuelo Arellano
  • Peter J. Balint-Kurti
Original Paper

DOI: 10.1007/s00122-008-0949-2

Cite this article as:
Zwonitzer, J.C., Bubeck, D.M., Bhattramakki, D. et al. Theor Appl Genet (2009) 118: 911. doi:10.1007/s00122-008-0949-2


B73 is a historically important maize line with excellent yield potential but high susceptibility to the foliar disease southern leaf blight (SLB). NC292 and NC330 are B73 near-isogenic lines (NILs) that are highly resistant to SLB. They were derived by repeated backcrossing of an elite source of SLB resistance (NC250P) to B73, with selection for SLB resistance among and within backcross families. The goal of this paper was to characterize the loci responsible for the increased SLB resistance of NC292 and NC330 and to determine how many of the SLB disease resistance quantitative trait loci (dQTL) were selected for in the development of NC292 and NC330. Genomic regions that differentiated NC292 and NC330 from B73 and which may contribute to NC292 and NC330s enhanced SLB resistance were identified. Ten NC250P-derived introgressions were identified in both the NC292 and NC330 genomes of which eight were shared between genomes. dQTL were mapped in two F2:3 populations derived from lines very closely related to the original parents of NC292 and NC330—(B73rhm1 × NC250A and NC250A × B73). Nine SLB dQTL were mapped in the combined populations using combined SLB disease data over all locations (SLB AllLocs). Of these, four dQTL precisely colocalized with NC250P introgressions in bins 2.05–2.06, 3.03, 6.01, and 9.02 and three were identified near NC250P introgressions in bins 1.09, 5.05–5.06, and 10.03. Therefore the breeding program used to develop NC292 and NC330 was highly effective in selecting for multiple SLB resistance alleles.

Supplementary material

122_2008_949_MOESM1_ESM.xls (151 kb)
Supplementary table 1 (XLS 151 kb)
122_2008_949_MOESM2_ESM.xls (37 kb)
Supplementary table 2 (XLS 37 kb)

Copyright information

© Springer-Verlag 2009

Authors and Affiliations

  • John C. Zwonitzer
    • 1
  • David M. Bubeck
    • 2
  • Dinakar Bhattramakki
    • 3
  • Major M. Goodman
    • 4
  • Consuelo Arellano
    • 5
  • Peter J. Balint-Kurti
    • 6
  1. 1.Department of Plant PathologyNorth Carolina State UniversityRaleighUSA
  2. 2.Pioneer Hi-Bred International, Inc.JohnstonUSA
  3. 3.Pioneer Hi-Bred International, Inc.Dallas CenterUSA
  4. 4.Department of Crop ScienceNorth Carolina State UniversityRaleighUSA
  5. 5.Department of StatisticsNorth Carolina State UniversityRaleighUSA
  6. 6.U.S. Department of Agriculture-Agricultural Research Service (USDA-ARS) Plant Science Research Unit and Department of Plant PathologyNorth Carolina State UniversityRaleighUSA

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