of Dissertation Presented to the Graduate School of the University of Florida in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy NONPARAMETRIC FUNCTIONAL MAPPING OF QUANTITATIVE TRAIT LOCI By Jie Yang August 2006 Chair: George Casella Major Department: Statistics Functional mapping is a tool for detecting major genes responsible for different phenotypic curves, de...

Quantitative trait loci, a genetic concept introduced in the 1940s, for explaining the inheritance of non-Mendelian traits, have been realized as particular fragments of chromosomes even unique genes in most crops in the 21st century. However, only very a small portion of QTL has been screened out by geneticists comparing to a great number of genes underneath the quantitative traits. These iden...

SUMMARY R/qtl is an extensible, interactive environment for mapping quantitative trait loci (QTLs) in experimental populations derived from inbred lines. It is implemented as an add-on package for the freely-available statistical software, R, and includes functions for estimating genetic maps, identifying genotyping errors, and performing single-QTL and two-dimensional, two-QTL genome scans by ...

The aim of this study was to refine the position of previously detected quantitative trait loci (QTL) on bovine chromosome 14 affecting milk production traits, using both linkage analysis (LA) and combined disequilibrium and linkage analysis (LDLA) methods, in Iranian Holstein dairy cattle. Analysis data was LRT (likelihood ratio test) and computed using the DMU (estimate the (co)variance compo...

Improvement of livestock has focused on the selective breeding of individuals with superior phenotypes. With the development of increasingly advanced statistical methods that maximise selection for genetic gain, this simple approach has been extremely successful in increasing the quantity of agricultural output. However, information now available on the organisation and functioning of the genom...

Statistical analysis system (SAS) is the most comprehensive statistical analysis software package in the world. It offers data analysis for almost all experiments under various statistical models. Each analysis is performed using a particular subroutine, called a procedure (PROC). For example, PROC ANOVA performs analysis of variances. PROC QTL is a user-defined SAS procedure for mapping quanti...

An association study conducted on 375 maize inbred lines indicates a strong relationship between Vgt1 polymorphisms and flowering time, extending former quantitative trait loci (QTL) mapping results. Analysis of allele frequencies in a landrace collection supports a key role of Vgt1 in maize altilatitudinal adaptation.

Genetic analysis of polygenic traits in rats and mice has been very useful for finding the approximate chromosomal locations of the genes causing quantitative phenotypic variation, so-called quantitative trait loci (QTL). Further localization of the causative genes and their ultimate identification has, however, proven to be slow and frustrating. A major technique for gene identification in suc...

We report the identification of quantitative trait loci (QTL) influencing wood specific gravity (WSG) in an outbred pedigree of loblolly pine (Pinus taeda L.). QTL mapping in an outcrossing species is complicated by the presence of multiple alleles (> 2) at QTL and marker loci. Multiple alleles at QTL allow the examination of interaction among alleles at QTL (deviation from additive gene action...

Maximum likelihood methodology was used to estimate effects of both a marker gene and a linked quantitative trait locus (QTL) on quantitative traits in a segregating population. Two alleles were assumed for the QTL. In addition to the effects of genotypes at both loci on the mean of the quantitative trait, recombination frequency between the loci, frequency of the QTL alleles and the residual s...