Genetic and chemo-divergence in eighteen core collection of Zingiber officinale from North-West Himalayas

• High molecular diversity was observed among North Western Himalayan Ginger population.
• Both molecular & oil based classification produced geographically concordant groupings.
• Hierarchical classification identified two distinct germplasm based on oil & molecular assessment.
• Potential role of microclimate in ascertaining essential oil chemistry.

Eighteen Zingiber officinale germplasm, collected from North-Western Himalayan region and showing significant differences in morphology and aroma, were characterized both chemically and genetically. Molecular analyses employing ISSR, SSR and IRAP techniques revealed moderate to high variations in clonally propagated ginger crop. ISSR analysis showed primers ISSR 4 and 8, having 9 polymorphic loci each, exhibiting 100% polymorphism while in SSR and IRAP primers RM153, RM278 and primer combinations of RT6 with RT3, RT4 and RT7, respectively showed 100% polymorphism. Essential oil evaluation revealed 31 major components based on GC analysis of hydro-distilled volatile oil extracted from rhizome of the collected population. Pair-wise Euclidean dissimilarity distance ranged from 3.37 to 16.93 revealing moderate variation in oil profile. The multivariate analyses of the oil based data could explain 99.9% of cumulative variation. Hierarchical analyses of molecular and oil profiles, grouped all the 18 genotypes into two major clusters, clearly distinguishing two germplasm (161 and 179) genetically and chemically both. The study also revealed two genetically similar germplasm from Theri (146 and 147) based on all the three techniques. This distinctness in oil and molecular profiling of the germplasm points towards distinct genotypes from different regions of North Western Himalayas. Further, ISSR profiling and essential oil array based classification produced geographically concordant groupings. The study revealed existence of moderate diversity in the unexplored North Western Himalayas.