Genetic diversity of yacon (Smallanthus sonchifolius (Poepp. & Endl.) H. Robinson) and its wild relatives as revealed by ISSR markers

Set of 29 accessions of Smallanthus sonchifolius, an important tuber crop from South America, and its three wild relatives were analysed using the Inter Simple Sequence Repeats (ISSR) markers. Seven primers out of 30 primers screened gave clear and reproducible spectra. The range of amplified bands was from 2500 bp to 300 bp. These seven primers generated in total 77 bands, from which 75 (97.4%) were polymorphic. Nei's genetic distances between samples varied from 0.01 to 0.24. The Shannon's index (I) was estimated as 0.0392. The UPGMA dendrogram created using the Neighbour joining method and based on the Dice's dissimilarity coefficient separated clearly the wild accessions from all S. sonchifolius samples, which remained close to each other, confirming the clonal origin and thus a very low genetic variability within the genus.