Resumen
The Szekler horse was a small-sized mountain horse of the Carpathian Mountains whose official stud book ceased to exist after WWII. Despite that, individual horses preserving all the characteristics of the Szekler horse remained scattered in remote areas. This study aims to evaluate the mitochondrial D-loop sequence (608 bp) of the founder population (n = 59) in 2021 of a breed reconstruction project started in 2012. D-loop showed 68 polymorphic sites. The number of haplotypes was 34, with haplotype diversity (Hd) 0.966 and nucleotide diversity (p) 0.02232. The value of Fu?s Fs statistic (-6.566) was significant (p < 0.001), which rejects a stable population status. Thirteen haplogroups (HG) were found with a nearly equal number of representatives (HG(n)?A (5), D (1), E (2), G (4), I (4), J?K (1), M (4), N (2), O?P (4), and R (1)). In contrast, the Q, L, and B HGs occurred in more horses (15, 9, and 7, respectively). Based on a large number of polymorphic sites and haplotypes, the founder stock is considered diverse. Since the HG Q is characteristic of Asian horses, the examined stock haplotype distribution reflects the eastern origin of the Hungarian horses brought from the East in 896 AD. It is complemented by the gene pool of horses from Europe (e.g., L) and the Middle East (e.g., B).