in order to identify the segre qtl affecting growth traits on the end region of chromosome 18 in a lori-bakhtiari sheep population, 162 animals from 5 paternal half-sib families were taken to be studied. phenotypic data included records of birth weight (bwt), weight at one month of age (w1), weaning weight (wwt), weight at six months of age (w6), chest circumference (gi6), body length (lg6), wi...

The consensus map is used for the verification of marker order, quantitative trait locus (QTL) mapping and molecular marker-assisted selection (MAS) in wheat breeding. In this study, a genetic named as Sp7A_G7A, was constructed using 5643 SNP markers two double haploid (DH) populations Spitfire × Bethlehem-7AS (Sp7A) Gregory (G7A), covering 4376.70 cM 21 chromosomes (chr) with an average interv...

Endosperm traits are trisomic inheritant and are of great economic importance because they are usually directly related to grain quality. Mapping for quantitative trait loci (QTL) underlying endosperm traits can provide an efficient way to genetically improve grain quality. As the traditional QTL mapping methods (diploid methods) are usually designed for traits under diploid control, they are n...

SINGLE VERSUS MULTIPLE MARKERS ........................................................................................................ 45 DETERMINING ASSOCIATIONS BETWEEN GENETIC MARKERS AND QTL WITH TWO MARKERS ................... 45 INTERVAL MAPPING .................................................................................................................................. 50 Maximum Li...

While extensive progress has been made in quantitative trait locus (QTL) mapping for diploid species, similar progress in QTL mapping for polyploids has been limited due to the complex genetic architecture of polyploids. To date, QTL mapping in polyploids has focused mainly on tetraploids with dominant and/or codominant markers. Here, we extend this view to include any even ploidy level under a...

Quantitative trait locus (QTL) mapping in animal populations has been a successful strategy for identifying genomic regions that play a role in complex diseases and traits. When conducted in an F2 intercross or backcross population, the resulting QTL is frequently large, often encompassing 30 Mb or more and containing hundreds of genes. To narrow the locus and identify candidate genes, addition...

An approach to increase the efficiency of mapping quantitative trait loci (QTL) was proposed earlier by the authors on the basis of bivariate analysis of correlated traits. The power of QTL detection using the log-likelihood ratio (LOD scores) grows proportionally to the broad sense heritability. We found that this relationship holds also for correlated traits, so that an increased bivariate he...

There has been a great deal of interest in the development of methodologies to map quantitative trait loci (QTL) using experimental crosses in the last 2 decades. Experimental crosses in animal and plant sciences provide important data sources for mapping QTL through linkage analysis. The Collaborative Cross (CC) is a renewable mouse resource that is generated from eight genetically diverse fou...

Recent studies report a surprisingly high degree of marker-to-marker linkage disequilibrium (LD) in ruminant livestock populations. This has important implications for QTL mapping and marker-assisted selection. This study evaluated LD between microsatellite markers in a number of breeding populations of layer chickens using the standardized chi-square (chi(2')) measure. The results show appreci...