Microsatellite marker resource creation, genetic diversity assessment and core prediction in Valeriana jatamansi Jones

Abstract

Valeriana jatamansi Jones, a potential ethno-medicinal herb of global importance faced an unprecedented threat of its habitat loss due to burgeoning global demand. Genome-wide microsatellites or simple sequence repeats (SSRs) marker resources are advantageous, unfortunately, such larger resources have not been explored for genetic improvement in V. jatamansi. In the present study, transcriptome-derived functionally relevant microsatellite marker resources comprising 7957 SSR markers with significant homology (66.3 %) with public functional databases were created. Interestingly, 103 putative functional SSR markers derived from unigenes exhibited substantial annotations with secondary metabolite biosynthesis, transcription factors, and transporters were synthesized and experimentally validated in diverse genotypes. SSR loci with good marker attributes (average alleles/ locus: 7.5; PIC: 0.44; resolving power: 5.25) were successfully utilized for genetic population structure analysis of 525 genotypes representing 29 geographically diverse populations. Despite representing three genetic populations, north-western Indian Himalayan regions (wIHR) exhibited with low genetic diversity (h: 0.22) with moderate gene flow (Nm: 0.97) and high molecular variance (71 %) within population. Moreover, the predicted core of 53 genotypes representing 21 diverse populations was validated successfully using NJ clustering and regression correlation (R² > 0.85). Additionally, future habitat suitability is predicted to decline in at least 49.89 % habitat area of V. jatamansi. Hence, climatic zones with improved suitability can be potential geographical areas for its conservation and sustainable cultivation. The current findings including huge molecular markers resources, diversity inferences, and identification of core collections will facilitate gene bank management, selection of potential parental groups/ cultivars for implementation of molecular breeding strategies, genetic improvement, and sustainable cultivations of V. jatamansi for industrial utilization.