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|Title:||Quantitative trait loci mapping for grain yield and other traits of agronomic importance in maize|
|Author(s):||Martinez, Edwin Robert|
|Doctoral Committee Chair(s):||Rocheford, Torbert R.|
|Department / Program:||Agronomy|
|Degree Granting Institution:||University of Illinois at Urbana-Champaign|
|Abstract:||Restriction fragment length polymorphisms (RFLPs) were used as molecular markers to identify chromosomal regions associated with quantitative traits in maize (Zea mays L.). Four Lancaster type inbreds were used to produce 66 F$\sb7$ recombinant inbred lines (RIs). One hundred-one RFLP loci were polymorphic among two or more of the parental inbreds and used to determine marker genotypes of the 66 RIs. Seventy-two of these markers that were polymorphic among the RIs were used to make associations with QTL. Phenotypic data were obtained from the evaluation of the line per se performance in replicated trials in 1992, and from testcross performance of the 66 RIs and four parents crossed to three diverse inbred testers. The testcross progeny were evaluated in replicated trials in two environments in 1991 and three environments in 1992.
Association of the line per se data sets with molecular marker data revealed marker-trait associations for plant height, ear height, days to anthesis, and days to silk emergence. In most instances, marker loci having significant associations for plant height were also associated with ear height. A number of marker loci influencing plant height were identified in the same genomic regions as major qualitative mutants that affect plant stature.
Association of yield trial data with molecular marker genotypes of the 66 RIs identified marker loci significantly associated with grain yield, grain moisture, stalk lodging, and root lodging. Some marker loci showed significant associations for grain yield with one or two testers, while others showed significant associations for grain yield with all three testers. Clusters of three or more RFLP loci significantly associated with grain yield on chromosomes 2S and 7L suggest the presence of major grain yield QTL at these locations.
Several marker loci were associated with more than one trait. Thus genes controlling these traits may map to the same chromosomal regions or have pleiotropic effects. Although a number of marker loci were associated with genotype by environment interactions (GXE) for grain yield among individual environments each year, the associations detected for combined environments within a year were stable between 1991 and 1992.
|Rights Information:||Copyright 1993 Martinez, Edwin Robert|
|Date Available in IDEALS:||2011-05-07|
|Identifier in Online Catalog:||AAI9411707|