Analysis of miRNA polymorphism during the selected developmental processes of flax

MicroRNAs represent small non-coding RNAs that play important role in regulating gene expression under various biotic and abiotic stresses as well as in different developmental stages of plants. They are involved in wide variety of biological and metabolic pathways of plants. The research was focused on the potential of selected miRNA-based molecular markers (miR156 and miR168) to map the polymorphism level of flax genome in the selected developmental stages (flower bud - flowering – boll development) as a reflection of the activity of specific miRNAs in these flax organs and tissues. The miRNA polymorphism was evaluated on 8 flax genotypes by miRNA-based molecular marker assays and data were supported by the morphology measurements on buds, flowers, petals and developing bolls. Extent of PCR amplification of miRNA fragments ranged from 40 bp to 200 bp (miR168a-F/miR-R primer pair) or 35 bp to 120 bp (miR156b-F/miR-R primer pair), respectively. MiRNA-based primers amplified in total 196, respectively 158 miRNA loci. Based on the results can be concluded that the representation of miR168 loci have increased according to developmental stages ascending (stage of bud, flower and boll). In overall miRNA156b loci profile in all three analyzed developmental stages is possible to observe the increase of miRNA loci amplification almost in all genotypes. Taking into account the genetic background of genotypes, based on the peak analysis profile of amplified miRNA loci, implemented by GeneTools software, was possible to identified unique loci in linseed and intermediate genotypes in individual developmental stages. Have been found out that only the genotype Bolley Golden differ from other genotypes in both analysis (molecular and morphological) if the variability of miR168 loci number in the flower bud growing stage was compared to the variability in trait petals colour in bud