Linkage analysis in unconventional mating designs in line crosses.

Linkage estimation and genetic map construction with genotyped DNA markers in plants preferentially employ a few maximally informative early-generation or recombinant-inbred mating designs. Fitting their recombination models to unconventional designs adapted to cultivar development (series of backcrossing, selfing, haploid-doubling, random-intercrossing, and sib-mating steps) distorts single- and multipoint linkage estimates even with dense marker coverage. Two methods are provided for correct linkage estimation in unconventional designs: fitting a correct multigeneration model, or correcting the estimates produced by fitting a one-generation model with any conventional software. These methods also support calculation of multilocus genotype frequencies and QTL-genotype distributions and are available in software.