Relevance of the genetic structure of natural populations, and sampling and classification approaches for conservation and use of wild crop relatives: potato as an example

Abstract

Crop wild relatives (CWRs) are wild taxa with close genetic relationships to species with direct socioeconomic importance. As essential components of natural habitats and agricultural systems, their conservation and sustainable use are vital. CWRs are ex situ conserved in germplasm banks as samples of natural populations (accessions). Most accessions have been assigned specific status according to the Taxonomic Species Concept, which presupposes that living organisms are at the end of speciation. Thus, the morphological and genetic variability that could be encountered in natural populations is disregarded, negatively affecting conservation of allelic frequencies and effective use in breeding. Passport information usually contains collection date and geographical data, but not reproductive behavior of the sampled population (which defines its genetic structure) and sampling strategies. For ex situ multiplications of original collections, no information is provided on the effectively used strategies. As information on how accessions were composed is lacking, conservation of the allelic frequencies from the originally sampled populations is unknown. Knowledge of reproductive biology of plant populations is of utmost importance to understanding their natural morphological and molecular variability and to developing appropriate methodological approaches for sampling, classifying, and ex situ multiplying to conserve gene frequencies for basic and applied purposes.