Genetic diversity of Patellifolia patellaris from the Iberian Peninsula, a crop wild relative of cultivated beets

The genetic diversity of Patellifolia patellaris has been investigated to generate information required for the organisation of a systematic genetic resources conservation action combining the best elements of the ex situ and in situ conservation concept. To this end, ten occurrences of the species were sampled on the Iberian Peninsula in Portugal and Spain. A total of 271 individuals was analysed using 24 microsatellite markers. The factorial analysis separated the material into two occurrences from Portugal, two occurrences sampled east of Gibraltar and six occurrences from the eastern Spanish coast. The pairwise genetic distance between occurrences and the complementary compositional differentiation among occurrences were calculated. The genetic distance values were used to construct an Unweighted Pair Group Method with Arithmetic Mean tree, which can be separated into four equidistant clusters. Two clusters are located in Portugal and two further clusters in Spain. The factorial analysis as well as the genetic distance and differentiation analysis indicate that the two occurrences from Portugal are clearly genetically different from the Spanish group of occurrences. Both occurrences have low population sizes and are therefore highly endangered. In situ conservation actions are urgently required for both occurrences. Further investigations are needed to organise better informed conservation actions for P. patellaris, namely to study genetic relationships between occurrences on the Spanish mainland and occurrences distributed on the Canary Islands, Madeira and Cape Verde Islands as well as in Morocco.