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Yield Effects of Two Southern Leaf Blight Resistance Loci in Maize Hybrids
Author(s) -
SantaCruz Jose H.,
Kump Kristen L.,
Arellano Consuelo,
Goodman Major M.,
Krakowsky Matthew D.,
Holland James B.,
BalintKurti Peter J.
Publication year - 2014
Publication title -
crop science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.76
H-Index - 147
eISSN - 1435-0653
pISSN - 0011-183X
DOI - 10.2135/cropsci2013.08.0553
Subject(s) - biology , introgression , quantitative trait locus , hybrid , inbred strain , agronomy , yield (engineering) , blight , resistance (ecology) , trait , plant disease resistance , genetics , gene , materials science , computer science , metallurgy , programming language
In this study we examined the effects of two quantitative trait loci (QTL) for southern leaf blight (SLB) resistance on several agronomic traits including disease resistance and yield. B73–3B and B73–6A are two near‐isogenic lines (NILs) in the background of the maize ( Zea mays L.) inbred B73, each carrying one introgression (called 3B and 6A respectively) encompassing a QTL for SLB resistance. Sets of isohybrid triplets were developed by crossing B73, B73–3B, and B73–6A to several inbred lines. A subset of these triplets for which the B73–3B and/or B73–6A hybrid was significantly more SLB resistant than the B73 check hybrid was selected and assessed in multi‐environment yield trials with and without disease. In the presence of SLB, 3B was associated with an approximately 3% yield increase over B73. 6A was associated with a yield advantage in the presence of SLB in specific pedigrees where the 6A resistance phenotype was highly expressed. Results suggested that both introgressions might confer a yield cost in the absence of SLB, but only introgression 6A was associated with a statistically significant reduction. We present evidence to suggest that the yield cost is associated with the resistance phenotype rather than with linkage drag.