Genetic resources in asparagus: diversity and relationships in a collection from different origins and breeding status

Asparagus (Asparagus officinalis) is a worldwide important vegetable. Assessing the genetic diversity and relationships in a germplasm collection is a key step in the design of breeding programmes. The aim of this work was to evaluate the genetic diversity in asparagus from a wide array of origins assessed by Sequence Related Amplified Polymorphism (SRAP) markers. Twenty-four accessions of A. officinalis from 13 different origins and one accession of A. pseudoscaber were considered. Sixteen combinations of SRAP primers were tested. A total of 329 bands were obtained (98.48% polymorphism). The average polymorphic information content was 0.20. Hierarchical clustering was carried out, the dendrogram was plotted with bootstrap p-values for the different branches and the Dice's distance matrix was represented by a Principal Coordinates Analysis. It was not possible to establish a clear origin-related grouping. The reduced cycles of selection accomplished along with the contemporaneous plant breeding and the open-pollinated nature of the species, could have precluded a marked differentiation in the species related to origins or cultivated to wild status. The genetic base of asparagus is not as narrow as previously thought. The information of the genetic relationships among asparagus germplasm could be useful to delineate crosses in order to seek potential hybrid vigour.