Integrated molecular and phytochemical characterization of Lemongrass (Cymbopogon sp.) germplasm from Vietnam and Laos

This study evaluated the genetic and phytochemical diversity of 35 Cymbopogon accessions from Vietnam and Laos using ITS and RAPD markers, as well as GC-MS analysis. The ITS sequencing identified two accessions as C. winterianus and 32 as C. citratus, revealing only two major haplotypes, which indicates low intraspecific variation. The RAPD analysis, conducted with eight polymorphic primers, generated 86 bands, yielding a polymorphism rate of 61.28%, indicating moderate genetic diversity and forming two distinct clusters corresponding to the two species. The lack of clear geographic structuring suggests extensive exchange of planting materials, resulting in the genetic homogenization of cultivated germplasm. The GC-MS profiling identified 27 volatile compounds, with citral isomers being the most prevalent (E-citral: 11.04–67.55%; Z-citral: 11.04–25.01%). Additionally, there was notable variation in geraniol, β-myrcene, and geranyl acetate. The integration of molecular and chemical data helped clarify the relationships between genotypes and chemotypes, providing a solid foundation for selecting elite germplasm with consistent essential oil quality, thereby supporting the sustainable breeding and conservation of lemongrass genetic resources in Southeast Asia.