Exploring genetic diversity and phytochemical variability in wild ramie ( <i>Boehmeria nivea</i> (L.) Gaudich. var. <i>tenacissima</i> (Roxb.) Miq.): Implications for conservation and breeding

Abstract Genetic diversity and phytochemical content are critical factors for enhancing the utility of wild plant species for breeding and conservation. In this study, we investigated wild ramie ( Boehmeria nivea (L.) Gaudich. var. tenacissima (Roxb.) Miq.) populations from six coastal and island regions of South Korea. Genetic diversity was assessed in 150 samples using genotyping-by-sequencing, which revealed high genetic differentiation (Fst = 0.438) among the populations. Notably, the observed heterozygosity ranged from 0.297 to 0.422, whereas the allele richness ranged from 1.256 to 1.323. These findings suggest significant genetic variability within and among the populations. Phytochemical analyses were conducted to measure total phenolic and flavonoid contents (TPC and TFC, respectively) over 2 years. The TPC varied significantly across regions and years, with averages ranging from 2.2 to 30.3 mgGAE/g in 2021 and 3.2 to 19.6 mgGAE/g in 2022. Similarly, the TFC values exhibited regional and annual differences with significant environmental influences. Although TPC showed strong genotype-by-environment interactions, TFC was predominantly affected by environmental factors. This study highlights the potential of wild ramie as a reservoir of genetic and biochemical traits for the development of improved cultivars with high antioxidant properties. By linking genetic diversity to phytochemical variation, this study highlights the importance of conserving wild genetic resources and optimizing their use in breeding programmes. These findings provide a foundation for further exploration of the genetic and environmental factors that influence economically valuable traits in wild plants.