Evaluation of genetic diversity and population structure of the medicinal plant Justicia adhatoda L. from North India using ISSR markers

Abstract

Justicia adhatoda L. is an important medicinal plant found in the form of shrub across the country up to an altitude of 1300 masl. It is used in treatment of respirartory diseases. In the present study, 32 pooled samples representing 140 accessions of J. Adhatoda from seven states of North India were analyzed for genetic diversity and structure using inter-simple sequence repeat (ISSR) markers. For this analysis, 23 ISSR markers were screened, and finally 15 ISSR primers were selected for analysis. Overall, these 15 polymorphic primers amplified 96 fragments with an average of 6.4 fragments per primer. The size range of amplified fragments was 300–2000 bp. Primers UBC834 and UBC846 amplified highest (9) number of fragments while UBC850 amplified lowest (3) fragments. Primer UBC855 exhibited highest (0.499) Polymorphism Information Content (PIC) value while UBC850 showed lowest (0.136) PIC value. Similarly, highest (3.906) Marker Index (MI) was shown by UBC834 and lowest (0.408) MI was shown by UBC850. Dendrogram showed that there were two major groups and one minor group with three samples in it. Although dendrogram was largely in concordance with geographical locations, some samples were placed exceptionally. Interestingly, samples from hilly regions grouped in one cluster except one sample. Factorial and structure results were in agreement to the results of dendrogram. STRUCTURE detected three clusters with some admixed individuals. The results of present study can be helpful in identifying unique accessions, devising conservation plans and strategic utilization methods of J. Adhatoda prevailing in the North Indian states.