SSR Markers for Monitoring an in vitro Core Collection of Populus tremula

摘要

Core collections efficiently preserve genetic diversity and facilitate collection management and "ex situ" conservation of genetic resources, Populus tremula (European aspen) is demanded by plant growers and breeders but there are very few data on thegenetic variation in the geographic distribution of this species in Spain Microsatellite markers are useful for the evaluation of genetic variability and identification due to their abundance and polymorphism. Six pairs of oligonu-cleotide primers designed for simple sequence repeats (SSR) of quaking aspen (P. tremuloides) were successfully used in European aspen. Number of alleles per locus were low in this species in comparison to outcrossed, long-lived woody perennials due to the importance of vegetative propagation by root suckers in aspen stands. Mean heterozygosity (0,475) was similar to that reported in quaking aspen. Cluster analysis suggests that postglacial migration of European aspen took place from the Pyrenees in two directions: westwardand southward through mountain ranges of the Iberian Peninsula. To preserve the allelic richness of the P. tremula in vitro collection in Spain, a core collection of 26 clones is proposed.