Genetic diversity is often evaluated using pedigree information. Currently, diversity can be evaluated in more detail over the genome based on large numbers of SNP markers. Pedigree- and SNP-based diversity were compared for two small related groups of Holstein animals genotyped with the 50 k SNP chip, genome-wide, per chromosome and for part of the genome examined. Diversity was estimated with coefficient of kinship (pedigree) and expected heterozygosity (SNP). SNP-based diversity at chromosome regions was determined using 5-Mb sliding windows, and significance of difference between groups was determined by bootstrapping. Both pedigree- and SNP-based diversity indicated more diversity in one of the groups; 26 of the 30 chromosomes showed significantly more diversity for the same group, as did 25.9% of the chromosome regions. Even in small populations that are genetically close, differences in diversity can be detected. Pedigree- and SNP-based diversity give comparable differences, but SNP-based diversity shows on which chromosome regions these differences are based. For maintaining diversity in a gene bank, SNP-based diversity gives a more detailed picture than pedigree-based diversity.
© 2012 Blackwell Verlag GmbH.