Mining simple sequence repeats inPicrorhiza kurroatranscriptomes for assessing genetic diversity among accessions varying for picrosides contents

Abstract

Picrorhiza kurroa (family Scrophulariaceae) is a high value medicinal herb used in herbal drug formulations like picroliv, picrolax, etc. It has been collected recklessly from its natural habitat posing endangered status for its existence, thereby necessitating characterization of genetic diversity for its sustainable utilization and conservation. In this study, picrosides content and genetic profiles of 26 accessions of P. kurroa from different locations in north-western Himalayas have been analysed. Picroside-I (P-I) content ranged from 0.37 to 2.7% in fresh shoots whereas total picrosides content (P-I+P-II) ranged from 3.7 to 10.9% in dry rhizomes. High picrosides content accession PKS-1 was identified, both for shoots and rhizomes. To study genetic diversity and correlate picrosides content with their genetic factors, genetic profiling was done using simple sequence repeats (SSRs) identified from P. kurroa transcriptomes. Out of 361 SSR primers tested on 26 accessions, 35 primers yielded polymorphic profiles. Overall low genetic diversity was observed in P. kurroa accessions. The highest polymorphism information content (PIC) of 0.55 was given by SSR marker PKSTS-P9 (TGGTG)4. Mean allele number was 2.97. Mean observed and expected heterozygosities were 0.597 and 0.452, respectively. Among all accessions Nei's genetic diversity (H) was 0.39 and Shannon's information index (I) was 0.58. Cluster analysis of STRUCTURE was comparable to DARWIN. Microsatellite markers would be helpful in the development of DNA diagnostics for the authentication of quality plant material as well as planning a genetic improvement strategy.

Isolation and HPLC assisted quantification of two iridoid glycoside compounds and molecular DNA fingerprinting in critically endangered medicinal Picrorhiza kurroa Royle ex Benth: implications for conservation

“…To the best of our knowledge, these markers have not, so far, been used in P. kurroa diversity assessment. A few studies have rather used SSR DNA markers (Katoch et al 2013;Shitiz et al 2017;Singh and Sharma 2020) for genetic analysis in P. kurroa. Likewise, HPLC-based quantitation of useful phytochemical compounds from roots and rhizomes of P. kurroa has been done to identify high yielding elite genotypes (Katoch et al 2011(Katoch et al , 2013Thapliyal et al 2012;Shitiz et al 2015;Sultan et al 2016;Mehra et al 2017;Soni and Grover 2019;Singh and Sharma 2020).…”