Comparative analysis of genetic diversity using molecular and morphometric markers in Andrographis paniculata (Burm. f.) Nees

Andrographis paniculata is a medicinal plant of immense therapeutic value. The present study was aimed to elucidate its genetic diversity based on morphochemical and RAPD markers from 53 accessions belonging to 5 eco-geographic regions. Analysis of variance and D2 statistics revealed significant differences in all the metric traits and sufficient inter-cluster distances indicating considerable diversity among the accessions. The complementary approach of RAPD was used to evaluate the genetic dissimilarities among all the accessions using 6 highly polymorphic primers. The average proportion of polymorphic loci across primers was 96.28%. The molecular genetic diversity based on Shannon index per primer averaged 5.585 with values ranging from 3.08 to 8.70 indicating towards wide genetic base. RAPD based UPGMA and D2 cluster analysis also revealed that various accessions available in different eco-geographic regions might have originated from native places of wild abundance. Similarity matrices were generated for molecular markers and morphometric data to determine the degree of congruence between the two. A highly significant but low correlation (r = 0.547, P < 0.001) was obtained thus implying the correspondence between the two. The species is hermaphroditic and a habitual inbreeder. The present study yielded a typical triangular congruence between its breeding system, morphometric traits and RAPD markers thus elucidating the usefulness of complementary approaches to make diversity analysis more explanatory and purposeful for optimum genetic amelioration and effective conservation of its genotypic variability.