Effects of genetic diversity and population structure on phenolic compounds accumulation in Hedychium spicatum

Hedychium spicatum Buch.-Ham. ex D.Don. is an important medicinal herb facing drastic shrinkage in its wild populations. In the present study, ISSR markers based genetic diversity of wild populations was correlated with the variation in phenolic compounds of the species using multiple regression analysis (MRA). A high level of genetic diversity and gene flow (Nm = 1.704) were recorded in species. Analysis of molecular variance revealed higher existence of genetic variation (89%) within populations than among populations. Bayesian model-based STRUCTURE analysis (at K = 2) and genetic differentiation revealed no direct relationship between genetic and geographical origins, which was further validated by Mantel's test. Phenolic compounds also exhibited significant variation (p < 0.05) among the populations. While developing marker-trait association using MRA, a total of 23 alleles exhibited significant positive (thirteen alleles) and negative (ten alleles) association with phenolic compounds. Associated alleles largely correlated with gallic acid and 3-hydroxybenzoic acid (10 each), while three alleles showed association with multiple phenolic compounds. This study opened a new doorway for genetic improvement and conservation priorities of the species.