Abstract
BackgroundRetrotransposons-RTNs, are main source of variations in plant genomes that copying and pasting themselves into different transposon and work by changing RNA back into DNA via reverse transcription. For that reason, they are largely utilized in plants as optimum molecular markers to determine DNA fingerprinting, genetic mapping, and genetic variability. ResultsInter-retrotransposon amplified polymorphisms (IRAPs) were used to measure genetic variability and structure in a collection of 118 sweet wormwood (A. annua) accessions identifying and amplifying 849 loci using 32 IRAP primers, derived from Rosaceae, Gramineae, and Solanaceae retroelements. Single IRAP primer Tnt1.OL16 based on RTN produced the maximum count of markers. Percentage of polymorphic loci (PPL), mean expected heterozygosity (He), number of effective alleles (Ne) and information index (I) of Shannon, in the studied collection were 95.80%, 0.30, 1.48 and 0.46, in the same order. AMOVA analysis showed nonexistence of significant genetic structures during structure analysis, however, the 4 populations had three clusters based on the NJ dendrogram that depicted a relatively higher level of genetic variation within each population. These clusters were approximately congruent with corresponding geographical distributions. ConclusionsIn conclusion, low genetic diversity of Iranian Sweet wormwood was detected that could be reduced through introduction of appropriate exotic or improved germplasm to reduce the effects of inbreeding depression.