Genetic Diversity and Population Structure of Rubus Accessions Using Simple Sequence Repeat Markers

Sixty-nine Rubus accessions were analyzed to determine the genetic relationships using simple sequence repeat (SSR) markers. Twenty-three SSR markers generated a total of 351 alleles from all accessions, with an average of 15.3 alleles per locus. The average value of polymorphism information content was 0.76, ranging from 0.52 to 0.91. As a result of population structure analysis, 69 Rubus accessions of six Rubus species were subdivided into six subpopulations. Four subpopulations included distinct Rubus species accessions; pop2 (Rubus crataegifolius var. subcuneatus, 2 accessions), pop3 (R. crataegifolius Bunge., 18 accessions), pop4 (R. fruticosus L., 3 accessions) and pop6 (R. coreanus Miq., 36 accessions) while The pop1 and pop5 mainly included R. idaeus L. and R. parvifolius L., respectively. In cluster analysis, 69 Rubus accessions were divided into three groups. Group I contained 35 Rubus accessions, which consisted of six Rubus species. Groups II and III had 30 and 4 Rubus accessions, respectively. They consisted of only R. coreanus. The uncertain diversity of species and artificial groups of the Rubus genus has created confusion with respect to the correct classification of the species at both commercial and scientific levels. The results of the present study will provide basic information for phylogeny, taxonomy and breeding programs of Rubus species.