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Abstract

Vostrá-Vydrová H., Vostrý L., Hofmanová B., Moravčíková N., Veselá Z., Vrtková I., Novotná A., Kasarda R. (2018): Genetic diversity and admixture in three native draught horse breeds assessed using microsatellite markers. Czech J. Anim. Sci., 63,[85][86][87][88][89][90][91][92][93] In this study, we aimed to estimate and compare genetic diversity of two native draught horse breeds and check the possible influence of Noriker breed population on these native breeds. Genetic analyses of relationships and admixture were performed in two native endangered draught horse populations (Silesian Noriker and Czech-Moravian Belgian horses) and one open breed (Noriker). Totally 104 alleles from 13 microsatellite loci were detected in 1298 horses. The average number of alleles per locus was the highest in the Czech-Moravian Belgian horse (7.62) and the lowest in the Silesian Noriker (7.31), the differences were non-significant, whereas the observed and expected heterozygosities per breed ranged from 0.680 (Czech-Moravian Belgian) to 0.719 (Noriker) and from 0.678 (Silesian Noriker) to 0.714 (Noriker). The estimates of Wright's F ST between each pair of breeds indicated a low level of genetic segregation. At the individual level across the analyzed population, formation of two clusters was observed with respect to historical breed development. Moreover, the membership probability outputs showed that the frequencies of alleles varied across the two main regions represented by the Czech-Moravian Belgian and other analyzed breeds. Our results indicated high genetic variability, low inbreeding, and low genetic differentiation, especially between Silesian Noriker and Noriker, which is caused by the high level of admixture. This high level of admixture was in accordance with geographical location, history, and breeding practices of the analyzed breeds. The Silesian Noriker and Noriker breeds seem to be the most genetically related and the decision to consider them as the same population is thus highly supported. The study provides data and information utilizable in the management of conservation programs planned to reduce inbreeding and to minimize loss of genetic variability.