Genetic diversity between and within the natural populations of Garcinia indica (Thouars) Choisy: A high value medicinal plant from Northern Western Ghats of India using ISSR markers

[Display omitted] •Garcinia indica is endemic to Western Ghats of India having high medicinal value.•High genetic diversity have been found between and within the natural population.•Present study proved ISSR Primer 857a can be used for the genus specific study.•Mantel test shows significant correlation between geographical and genetic distance.•Based on the study conservation strategies have been evolved. The present study reveals genetic diversity between and within the natural populations of Garcinia indica which is an endemic and medicinally important tree species from the Western Ghats of India. During the study extensive field survey was carried out to different parts of the region and collected leaf samples from 11 different locations to assess genetic diversity between populations. To understand the genetic diversity within the population, leaf samples were collected from seven different locations (accessions) spread over the single large population at Amboli, Maharashtra. Out of 21 ISSR primers screened, 12 primers produced reproducible, clear banding pattern. A total of 127 bands amplified for the samples analyzed in between the populations, among them 119 were polymorphic and percent polymorphism varied from 80 to 100% per primer. Genetic diversity within the population shown a total of 85 amplified bands, out of which 74 were polymorphic and polymorphic percentages varied from 60 to 100% per primer. The other genetic diversity parameters revealed high diversity and differentiation in both between populations (percent polymorphism = 93.87%, h = 0.3196, na = 1.82, ne = 1.37, I = 0.41, Ht = 0.26 and GST = 0.81) and within population (percent polymorphism = 84.80%, h = 0.36, na = 1.88, ne = 1.56, I = 0.48, Ht = 0.32 and GST = 0.86). Dendrogram revealed two main clusters for both between and within the natural populations based on altitudinal variation and geographical distribution of the species which is significantly supported by Mantel correlation test for geographic and genetic distance among populations. G. indica is highly exploited for various traditional and pharmaceutical preparations and have demand in the national and international markets, the understanding of genetic diversity among the natural populations especially in Konkan regions where plants are abundant will help in conservation of potential germplasm and utilization for breeding programme for large scale cultivation by farmers.