GENETIC-ANALYSIS AND MANAGEMENT IN SMALL POPULATIONS - THE ASTURCON PONY AS AN EXAMPLE

Geneticists are faced with various problems when managing small natura l populations (e.g. high inbreeding, loss of economic value). We propo se here the management of a small population through the example of th e Asturcon (a Celtic pony population) by examining two sources of info rmation: a studbook created in 1981 and the polymorphism of ten micros atellite markers chosen according to the recommendations of ISAG (Inte rnational Society of Animal Genetics). This information allows us to e stimate several genetic parameters useful in assessing the genetic sit uation of the population in order to propose conservation strategies. Results show the reliability of molecular information in populations w here no studbook exists. Overall inbreeding value (F) and fixation ind ex (F-IT) are moderate (F = 0.027; F-IT = 0.056), effective number of founders is small (n = 22), and the population is divided into three d istinct groups (F-ST = 0.078; P < 0.001). The molecular heterozygosity (H-M = 71.2%) computed in a random sample gives an accurate vision of the real inbreeding. These parameters and the application of the conc ept of average relatedness allow us to recommend to the breeders the c hoice of the best matings to control the inbreeding level while mainta ining a low paternity error rate. (C) Inra/Elsevier, Paris.