We conclude that paradigm shifts in soil mapping and classification can be better explained by not only their correlation to historical improvements in scientific understanding, but also by differences in purpose for mapping, and due to advancements in geographic technology.
Therefore, the different programs, algorithms, and functions used for mapping may explain the differences in map length reported by the present and previous studies.
It has been found by other studies that the two types of analyses generally yield inconsistent results, but can agree if the differences between the two methods (caused by differences in the precision for mapping QTL location, ability to account for multiple linked QTL and due to over estimation of what are sometimes modelled as fixed SNP effects), are accounted for [ 40].
By comparing the map positions in Table S3 (Additional File 13) one can see that there is perfect co linearity of shared marker order between the two maps, though there are differences in map distances throughout each linkage group.
The discrepancies between the two studies can probably be explained by differences in the ways that the lineage maps were derived.
In previous studies (Additional file 1: Table S1), comparisons were made difficult by differences in thresholds (genome-or chromosome-wide), maps (parental or consensus) and studied traits, even if most studies used a common phenotyping protocol (European project MASTER, ended in 2005).
Due to differences in mapping methodology and scale, NRCS data could not be quantitatively compared, and other comparisons were complicated by differences in flood hazard class criteria and terminology between maps.
The column denoted by "0 bases different" reports sequencing reads when allowing for no differences in mapping to the reference.
Differences in mapping populations, genotypes, and environments can yield heterogeneous results in QTL mapping [ 3, 8].
The amount of variance explained by difference in genotype differs in the four mapping populations, with LerxCol and LerxCvi having the highest heritabilities.
