SummaryIn the 1980s, a conservation programme involving a feral horse population, the Retuertas horses from the Guadalquivir marshes, was started in the Doñ ana National Park. The analysis of an extensive genetic survey of this population, which now numbers 100 animals, and 10 additional European and North African breeds using DNA polymorphisms from 22 microsatellites is presented. Highly significant fixation indexes were obtained for all pairwise comparisons between the Retuertas population and other breeds. A population neighbour-joining breed phenogram was built using different distance measures, but the Retuertas population failed to cluster with either of the two major clades of European and North African breeds, highlighting its uniqueness. In fact, the Retuertas population was positioned at the base of the trees, which were rooted using donkey samples. Furthermore, assignment tests and the individual Q-matrices obtained with the STRUCTURE programme isolated the Retuertas breed from the other breeds with only four K groups. Interestingly, some local semi-feral horses, known as Marismeñ o, also currently living in the Guadalquivir marshes, have some microsatellite genotypes that fall well within the Retuertas cluster. This raises the possibility of incorporating horses from the Marismeñ o population in a future conservation programme.

SummaryThe Asturcón Pony was on the verge of disappearing during the decade of the 1970. The creation of A. C. P. R. A (Breeders Association of Asturcón Ponies) and the measures undertaken by this association have made possible the present population of 400 of these animals and future perspectives for them to be bred at large for agrotourism and children's training in horseback riding and other equestrian sports. In spite of the fact that the recovery of the breed is being carried out with few individuals, our results show a high genetic variability. Analysing the allelic frequencies of blood polymorphism, we have obtained an average heterozygosity of 0.3649±0.1070 akin to that of other ponies such as the Dartmoor (0.3396±0.1060), Shetland (0.3158±0.1246 or the Connemara (0.3797±0.1000) and even superior to breeds such as the P. S. I. (0.2857±0.1194) and the Arabian (0.2299±0.0969).