RAPD markers reveal genetic diversity in Salix purpurea L.
The bark of purple osier willow (Salix purpurea L.) constitutes a particularly valuable raw material which is used for the production of natural aspirin. The content of salicylic glycosides in the bark is differential and depends on genotype, therefore continued selection is necessary to find high-yielding crop varieties of S. purpurea with a high salicylic glycoside content of the bark. The objective of this study was an evaluation of the genetic diversity of a collection of S. purpurea genotypes and their hybrids with the use of RAPD markers. The experiment involved 39 of the 60 tested oligonucleotide primers generating polymorphic amplification products. The polymorphism index of RAPD markers was 88.8% in all studied genotypes and 75.5% in S. purpurea genotypes. The values of Nei's genetic identity statistics ranged from 0.443 to 0.928. Nei's genetic distance values were used to build a dendrogram using unweighted pair group method with arithmetic mean (UPGMA). The considerable genetic diversity observed among the studied genotypes enabled us to identify parental forms suitable for crossing aimed at producing transgressive progeny, which would provide a basis for the selection of initial breeding materials. In addition, the determination of the genetic diversity of the collected genotypes may contribute to developing a mapping population, which would serve as a tool for the identification and localization of QTL corresponding to yield and salicylic glycoside content.