Genetic structure of Indian valerian (Valeriana jatamansi) populations in western Himalaya revealed by AFLP

A comprehensive overview of breeding strategy to improve phenotypic and quality traits in Valeriana jatamansi Jones

Valeriana jatamansi is a high value perennial herb that grows at an altitude of 1000-3000 MASL in the Indian Himalayan Region and is used in the Ayurvedic, Unani and Chinese systems of medicine. The plant extracts and essential oil (EO) obtained from its roots are used in the pharmaceutical, aromatic and flavouring industries. On account of high global annual demand and lack of organized cultivation of this herb, it is mostly collected from the wild causing depletion of the natural populations and also leading to variable produce making it unsuitable for industrial use. Therefore, to promote its cultivation, it becomes imperative to develop varieties with uniformity. Significant variations have been reported in V. jatamansi populations in terms of underground biomass accumulation, essential oil and valepotriates indicating potential of genotypic variability for effective selection. The review focuses on the diversity and variations at inter- and intra-population levels for phenotypic traits, variations for different active constituents and scope of improvement through selective breeding in V. jatamansi. The species has cross-pollinated breeding behaviour on account of floral dimorphism and presents unique opportunities for development of homozygous progeny lines through controlled self/sib-pollination by applying the breeding methods described in the review for population improvement. The germplasm resources of unique and improved selections can be maintained clonally to ensure their true-to-type identity. This review article was framed in the year 2022 after thoroughly studying the literature from the year 1919-2022. The study focuses on the variations in V. jatamansi which could be used to maximize the production through various breeding techniques for biomass and yield of different active constituents to meet the requirements of pharmaceutical and aroma industries.

Chemical Diversity of Essential Oil of Valeriana jatamansi from Different Altitudes of Himalaya and Distillation Methods

Valeriana jatamansi is an important temperate herb that is used in the pharmaceutical and essential oil industries. In India, this species is now on the verge of extinction due to the over-exploitation of its rhizomes from its natural habitat. It is hypothesized that the variations in bioactive compounds in its essential oil are very high among the wild populations as well as cultivated sources. Thus, this study was conducted to evaluate the chemical profiling of essential oil of four wild populations (Rupena, Kugti, Garola, and Khani) and two cultivated sources (CSIR-IHBT, Salooni), which were distilled at three consecutive days. The variation in oil concentration in roots/rhizomes was found significant (p ≤ 0.05), and the maximum value (0.35%) was registered with the population collected from Kugti and Khani. In essential oil, irrespective of population and distillation day, patchouli alcohol was the major compound, which ranged from 19 to 63.1%. The maximum value (63.1%) was recorded with the essential oil obtained from Garola’s population and distilled on the first day. The percentage of seychellene was abruptly increased with subsequent days of extraction in all the populations. The multivariate analysis revealed that the essential oil profiles of Rupena, Kugti, Garola, and CSIR-IHBT populations were found to be similar during the first day of distillation. However, during the second day, Rupena, Kugti, Khani, and CSIR-IHBT came under the same ellipse of 0.95% coefficient. The results suggest that the population of Kugti is superior in terms of oil concentration (0.35%), with a higher proportion of patchouli alcohol (63% on the first day). Thus, repeated distillation is recommended for higher recovery of essential oil. Moreover, repeated distillation can be used to attain V. jatamansi essential oil with differential and perhaps targeted definite chemical profile.

Clonal Propagation of Valeriana jatamansi Retains the Essential Oil Profile of Mother Plants: An Approach Toward Generating Homogenous Grade of Essential Oil for Industrial Use

Valeriana jatamansi Jones (Syn. V. wallichii DC.) is an aromatic, medicinal herb used as a tranquilizer and in treating sleep disorders. Rhizome is mainly used to extract essential oil (EO) and valepotriates. High quality and economic yield of rhizomes are available in the third year of growth. Therefore, the cultivation of V. jatamansi is not picking up, and over-exploitation of this plant from wild habitats to meet the increasing demand of the pharmaceutical industry is the cause of threat to the genetic diversity of the species. Further, collections from the wild are heterogeneous, resulting in variable produce. The development of clonal lines can ensure uniform quality and yield of rhizome biomass. An effective clonal propagation method was standardized using different hormonal concentrations of naphthalene acetic acid (NAA) on apical shoot cuttings from the selected clone CSIR-IHBT-VJ-05 for different time durations and raised over various planting media. NAA treatment of 50 ppm concentration for 30 min was found optimum for root induction in apical shoots of V. jatamansi. Variations for EO composition within the clone were non-significant, while samples of the control population were variable. The best quality EO (patchouli alcohol ∼62%) was available during the third year of plant growth. A propagation technique for large-scale quality plant material (QPM) production has been standardized to reduce the stress over natural resources and promote V. jatamansi for use in the aromatic and pharmaceutical industry.

Comparative and Functional Screening of Three Species Traditionally used as Antidepressants: Valeriana officinalis L., Valeriana jatamansi Jones ex Roxb. and Nardostachys jatamansi (D.Don) DC

The essential oils (EOs) of three Caprifoliaceae species, the Eurasiatic Valeriana officinalis (Vo), the Himalayan Valeriana jatamansi (Vj) and Nardostachys jatamansi (Nj), are traditionally used to treat neurological disorders. Roots/rhizomes micromorphology, DNA barcoding and EOs phytochemical characterization were carried out, while biological effects on the nervous system were assessed by acetylcholinesterase (AChE) inhibitory activity and microelectrode arrays (MEA). Nj showed the highest inhibitory activity on AChE (IC₅₀ 67.15 μg/mL) followed by Vo (IC₅₀ 127.30 μg/mL) and Vj (IC₅₀ 246.84 μg/mL). MEA analyses on rat cortical neurons, carried out by recording mean firing rate (MFR) and mean bursting rate (MBR), revealed stronger inhibition by Nj (IC₅₀ 18.8 and 11.1 μg/mL) and Vo (16.5 and 22.5 μg/mL), compared with Vj (68.5 and 89.3 μg/mL). These results could be related to different EO compositions, since sesquiterpenes and monoterpenes significantly contribute to the observed effects, but the presence of oxygenated compounds such as aldehydes and ketones is a discriminating factor in determining the order of potency. Our multidisciplinary approach represents an important tool to avoid the adulteration of herbal drugs and permits the evaluation of the effectiveness of EOs that could be used for a wide range of therapeutic applications.

Genetic and biochemical diversity among Valeriana jatamansi populations from Himachal Pradesh

Valeriana jatamansi Jones is an important medicinal plant that grows wild in Himachal Pradesh, India. Molecular and biochemical diversity among 13 natural populations from Himachal Pradesh was assessed using RAPD and GC-MS to know the extent of existing variation. A total of seven genetically diverse groups have been identified based on RAPD analysis which corroborated well with the analysis based on chemical constituents. The essential oil yield ranged from 0.6% to 1.66% (v/w). A negative correlation between patchouli alcohol and viridiflorol, the two major valued constituents, limits the scope of their simultaneous improvement. However, other few populations like Chamba-II and Kandi-I were found promising for viridiflorol and patchouli alcohol, respectively. The analysis of chemical constitution of oil of the populations from a specific region revealed predominance of specific constituents indicating possibility of their collection/selection for specific end uses like phytomedicines. The prevalence of genetically diverse groups along with sufficient chemical diversity in a defined region clearly indicates the role of ecology in the maintenance of evolution of this species. Sufficient molecular and biochemical diversity detected among natural populations of this species will form basis for the future improvement.

Genomic profile of the plants with pharmaceutical value

There is an ample genetic diversity of plants with medicinal importance around the globe and this pool of genetic variation serves as the base for selection as well as for plant improvement. Thus, identification, characterization and documentation of the gene pool of medicinal plants are essential for this purpose. Genomic information of many a medicinal plant species has increased rapidly since the past decade and genetic resources available for domestication and improvement programs include genome sequencing, expressed sequence tags sequencing, transcript profiling, gene transmit, molecular markers in favor of mapping and breeding. In recent years, multiple endeavors have been undertaken for genomic characterization of medicinal plant species with the aid of molecular markers for sustainable utilization of gene pool, its conservation and future studies. Recent advancement in genomics is so fast that only some researches have been published till date and to a large extent documentation is restricted to electronic resources. Whole genome profiling of the identified medicinal plant species, carried out by several researchers, based on the DNA fingerprinting, is well documented in the present review. This review will facilitate preparing a database of the widely used, economically important medicinal plant species, based on their genomic organization.