No abstract

No 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.

The knowledge about the level of genetic diversity and population structure in natural populations of Artemisia annua L. is a primary step in breeding programs for development of new cultivars with higher artemisinin level and better quality of secondary metabolites composition. We used PCR-based “retrotransposon-microsatellite amplified polymorphisms” (REMAPs) to study insertional polymorphism in A. annua genome to assess genetic variability and population structure in a collection of 118 accessions collected from north and northwest of Iran. Twenty-five primer combinations of 10 retrotransposon and seven ISSR primers amplified a total of 693 clear and unambiguous fragments in the studied accessions. The average number of bands, polymorphic bands, polymorphism, effective number of alleles, Shannon’s information index and expected heterozygosity were 27.72, 24.76, 88.14%, 1.47, 0.42 and 0.28, respectively. The analysis of molecular variance revealed high genetic variation present within sampled geographical regions. Distance-based cluster analysis assigned the studied accessions into four clusters according to their geographical origin, which were also confirmed by principal coordinate analysis. In model-based Bayesian clustering, the maximum value of Δ k was obtained when the collection of 118 assayed A. annua accessions assigned into two subgroups ( K = 2). The results showed the high genetic variation in the collection of Iranian sweet wormwood which revealed by REMAP markers indicating the reliability and efficiency of this marker system for analysis of genetic diversity and population structure of A. annua . Supplementary Information The online version contains supplementary material available at 10.1007/s40415-022-00860-x.