Unraveling the genetic diversity and population structure of Mesua ferrea L. Through RAPD and ISSR markers for effective conservation

This study analyzed the genetic diversity and population structure of Mesua ferrea L. in Bangladesh using Random Amplified Polymorphic DNA (RAPD) and Inter Simple Sequence Repeat (ISSR) markers. A total of 63 individuals from six geographically distinct populations were analyzed. Thirty-nine and eighty-five polymorphic bands were generated using RAPD and ISSR primers, respectively, both showing 100 % polymorphism. ISSR markers showed higher polymorphic information content (PIC) (0.336 ± 0.055) and resolving power (Rp) (3.550 ± 1.47) than RAPD (PIC: 0.320 ± 0.055; Rp: 1.582 ± 0.813), indicating greater efficiency in detecting genetic variation. Genetic diversity parameters revealed substantial variability, with the Moulvibazar and BFRI populations showing the highest Nei's diversity and Shannon indices. UPGMA dendrograms and Principal Coordinate Analysis (PCoA) indicated two major genetic clusters with significant overlap among populations, reflecting weak genetic structuring and strong gene flow. STRUCTURE analysis identified four and three genetic clusters (K = 4 and K = 3) for RAPD and ISSR data, respectively, confirming admixture among populations. AMOVA revealed that 65-77 % of total genetic variation occurred within populations, while 6-17 % was among populations, signifying moderate differentiation. The findings demonstrate high within-population diversity and genetic connectivity across regions. ISSR markers exhibited superior resolution, whereas RAPD captured broader inter-population relationships. Overall, the combined use of RAPD and ISSR markers provided complementary insights into the genetic architecture of M. ferrea. Populations from Moulvibazar, BFRI, and SUST, identified as genetically diverse and admixed, are recommended as priority sources for conservation, restoration, and breeding programs to ensure long-term genetic sustainability of the species.