Genetic diversity and population structure of Clerodendrum serratum (L.) Moon using CBDP, iPBS and SCoT markers

Abstract

An investigation into the level of genetic diversity and population structure of medicinally important endangered Clerodendrum serratum was conducted for the first time in Manipur, a North-Eastern state of India, using CAAT box-derived polymorphism (CBDP), inter primer binding site (iPBS), and start codon targeted (SCoT) markers. The comparative analysis of the three marker systems revealed SCoT to be the most effective among other markers in detecting polymorphism and genotype differentiation. Mantel test revealed a positive correlation between CBDP and iPBS (r = 0.22), SCoT and CBDP (r = 0.48), and iPBS and SCoT (r = 0.62), indicating the effectiveness of each marker system and reliability of using them in conjunction with one another to generate accurate and consistent results. Marker analysis disclosed a moderately high estimate of moderately high gene flow (Nm = 1.133) between the populations which resulted in low genetic differentiation (Gst = 0.310) among populations. Mantel test disclosed a non-significant correlation between the geographic and genetic distances between the 8 different populations of C. serratum. Analysis of molecular variance (AMOVA) showed the existence of genetic variation (66 %) within the population and the remaining variation (34 %) among the populations. Unweighted pair group arithmetic mean method (UPGMA) dendrograms constructed based on pooled CBDP, iPBS, SCoT marker data produced clusters similar to the pattern generated by the two-dimensional principal coordinate analysis (PCoA). Bayesian model STRUCTURE analysis of C. serratum populations based on CBDP, iPBS, and SCoT markers gave three genetic clusters (K = 3), but the pooled marker data generated 5 different genetic groups with high admixture. GENELAND further assigned the 8 populations comprising 97 individual genotypes into two main genetic pools. The genetic information obtained from the present investigation will contribute to offering proper recommendations for the effective management and conservation of endangered C. serratum plants in the region.