Genetic Variability and Structure of Fragaria nilgerrensis Schlecht. Germplasm in Sichuan Province

Fragaria nilgerrensis Schlecht. (wild strawberry) is widely distributed in Southwest China, characterized by stress tolerance and the fruits of a notable peach aroma. So far there is only limited knowledge of variability and genetic structure in this species. Using AFLP markers, we investigated the genetic variability of 37 plants of F. nilgerrensis sampled in six main mountain areas of Sichuan Province and analyzed their genetic structure. Genetic similarity according to Nei and Li was used for cluster analysis based on UPGMA method and Agglomerative Hierarchical Clustering. Stratification of plants into more distinctive genetic groups was determined using Bayesian structure analysis. Six primer combinations produced a total of 1302 fragments of which 818 (62.8%) were polymorphic. Bayesian analysis showed the 37 plants of F. nilgerrensis grouped into five distinctive genetic groups. Most of the plants from the same mountain area clustered into the same genetic group, indicating each area as an area with the unique genetic profile. The genetic parameters analyzed here indicate a huge genetic variability of F. nilgerrensis in Sichuan Province. Our results provide reference data for surveying and protecting the germplasm resources of F. nilgerrensis that could be used in strawberry breeding programs.