Genetic diversity evaluation of core collection gene bank using simple sequence repeat marker of Acorus calamus L.: An important aromatic species

Acorus calamus L. is an important medicinal and aromatic plant having economic and medicinal properties. In the present research, molecular diversity analysis was performed using 138 Acorus calamus accessions obtained from the varied regions of Northeast India. All the collected germplasm was maintained at the Council of Scientific and Industrial Research-North East Institute of Science and Technology (CSIR-NEIST) experimental farm, Jorhat, India. A molecular diversity study was conducted by employing 30 primers screened from 55 simple sequence repeat (SSR) primers based on their polymorphic nature. An average of 99.58% polymorphism was exhibited with a total of 186 polymorphic alleles shown by the selected SSR primers. To estimate the variations among A. calamus accessions, an analysis of molecular variance (AMOVA) was also performed. The genetic diversity among the population was found to be 28% and genetic variations of 72% were observed within the population. Genetic variations within and among populations were found significant with P value of 0.001. The analysis of population-based genetic diversity parameters revealed an average value of 1.84 for the observed number of alleles (Na), 1.48 for an effective number of alleles (Ne), 0.28 for Nei’s genetic diversity index (h), and 0.42 for Shannon's information index in four grouped populations. All the 138 accessions of A. calamus were subdivided into three clusters of dendrogram based on unweighted pair group method with arithmetic mean (UPGMA) analysis. Principal component analysis (PCoA) was further performed and a biplot was constructed for the validation and confirmation of the clusters. Moreover, three genetically diverse populations were also detected by the use of structure harvester software. Until now, there are no such reports on the analysis of the genetic diversity of this industrially important crop using SSR markers. So, it can be considered as the first report on the molecular diversity of A. calamus which will be helpful for the crop improvement, conservation, and identification of the elite genotypes.