Link to home

Quantitative Trait Loci Associated with Resistance to Gray Leaf Spot of Corn

September 2000 , Volume 90 , Number  9
Pages  1,018 - 1,025

M. J. Clements , J. W. Dudley , and D. G. White

Department of Crop Sciences, University of Illinois, Urbana 61801

Go to article:
Accepted for publication 7 February 2000.

The susceptible parent FR1141, the resistant parent 061, the F1 cross, and 301 families selfed once from backcrosses to the susceptible parent were evaluated for gray leaf spot (GLS) severity for two years in Urbana, IL, and one year in Andrews, NC. Linkage between ear height and GLS severity was suspected. Therefore, plant height characteristics were noted for two years in Urbana, IL. Eighty-six polymorphic probes were used to construct a random fragment length polymorphism linkage map, and the presence, locations, effects, and interactions of quantitative trait loci (QTL) associated with GLS, plant and ear height were determined. Five QTL were significantly associated with GLS resistance across all environments and rating periods. These five regions are associated with additive effects on phenotype and account for between 51.0 and 58.7% of the phenotypic variation associated with GLS severity. Additionally, six QTL were identified with maturity-dependent associations to GLS severity. Heritability of GLS resistance was estimated to be approximately 0.73. Four QTL were identified with associations to ear height relative to total plant height. One of the four was associated with higher ear height and GLS resistance.

Additional keywords: Cercospora zeae-maydis, maize, molecular markers.

© 2000 The American Phytopathological Society