Phytochemical Diversity in Relation to Cytogenetic Variability in Inula racemosa Hook.f., an Endangered Medicinal Plant of Himalayas

Abstract

Inula racemosa, a resourceful critically endangered medicinal herb in the Himalayas is traditionally utilized to cure various human disorders. The species is a wealthy source of sesquiterpene lactones has many pharmacological properties. To quantify and identify the best genetic stocks for a maximum build-up of desired metabolites (isoalantolactone and alantolactone) among existent cytotypes in the species, LC-MS/MS analysis was made. The other comprehensive experiments carried out at present included detailed meiotic examinations of different populations collected from different areas of Kashmir Himalayas. The results presented the occurrence of variable chromosome numbers as n=10 and n=20 in different populations, but the tetraploid cytotype (n=20) is new for the species. The LC-MS/MS investigation revealed significant variability in the content of sesquiterpene lactones in different plant tissues (stem, leaf, and root). An upsurge in the quantity of isoalantolactone and alantolactone was noticed with increasing ploidy levels along the increasing altitudes. Therefore, a habit to accumulate abundant quantities of secondary metabolites and increased adaptability by species/cytotypes thriving at higher altitudes is seen among tetraploid cytotypes during the present investigation. Also, the chromosomal variations seem to enhance the flexibility of polyploid species primarily at upper elevations. Thus, the present study strongly provides quantification of elite cytotypes/chemotypes with optimum concentration of secondary metabolites.