Plants use light sources both as energy sources and to adjust to environmental conditions

Studies in Brassica oleracea showed the same asymmetrical interploidy compatibility pattern as we observed in C. sativa; that is, when the paternal parent had the higher chromosome number, there was a lethal disruption in embryo development, whereas when the maternal parent contained a chromosome excess, viable seeds were formed . Imbalances in the expression levels of the AGAMOUS-like gene families appeared to play important roles in the endosperm and embryo development failure in B. oleracea . Research on potato showed that the strength of triploid block can vary among genotypes . Therefore, research into multiple genotypes and gene expression variations may be useful in obtaining a full understanding of asymmetrical compatibility and asymmetric triploid blocking in C. sativa as a species. Plant growth, development, metabolism, and morphology can be greatly manipulated by the quality and duration of light . Light quality denotes the color or wavelength adjacent to the surface of the plant, which affects plant growth, foliar and floral morphology, biochemical changes, and photosynthesis process . It was demonstrated that wavelengths ranging from 430 to 500 nm is effective for pigmentation, secondary metabolites production, chloroplast development, and functioning in photosynthesis . The wavelength range 500–600 nm also influences chlorophyll production and photosynthetic activity . On the other hand, the wavelength range 640–670 nm was found effective in leaf area, photosynthetic activity, and plant biomass accumulation . Light quality and quantity also have a drastic effect on the excitation of PS I and PS II, which is directly interlinked with photosynthesis processes . Light spectral quality considerably affects plant shoots and roots regarding their growth and morphology, and their interaction .

In the present experiment, the longest RL was recorded from L1 and L9, and the opposite result was found from L2 and L6 . In a previous study, plant height and weight were found better in red light; RL was longer in red and natural light while shorter in white and blue light under greenhouse conditions . In the present study, the addition of FR light to R and B increased the LL and LW, best trimming trays while decreasing the LN and NN . It was reported that the cannabis plant attained a higher plant height and leaf area in white light compared to the combination of red and blue light , but we did not find any significant differences in those morphological traits under similar light conditions. In a previous study, the addition of FR to R and B decreased the LL and SL of tomato plants while no significant effect was observed for RL and LN . The PCA analysis revealed that LL, LW, and SL were negatively correlated with LN and NN . Results indicated that a higher number of leaves and branches will make the hemp plants shorter in size with narrow leaves and vice versa. Importantly, LN and NN were closely associated with the treatments L9, L10, and L11, whereas LL and LW manifested an opposite relationship with them . This may be due to the influence of UV-A, which reduced the leaf area but increased the leaf number and branching. Generally, UV radiation impacts the phytohormone auxin levels higher in leaf regions with high division activity and lower in areas of cell expansion , resulting in a decrease in adaxial pavement cell expansion . Furthermore, compared to white light, PFW, PGR, and NN increased in most LED composition. The results indicate the incapability of monochromatic white light for plant growth and development, as it also resulted in lower TSC and sucrose accumulation in most cases. The PCA analysis indicated a negative relationship between the L2 treatment and NN, PFW, PGR, TSC, and sucrose, which also had a positive correlation with the parameters. An earlier study showed that the Chl a and Chl b contents increased in lettuce, basil, spinach, kale, and pepper under different combinations of R and B . In our study, the Chl a and b of hemp plants were significantly increased, but the chlorophyll a/b ratio and Car drastically decreased in the L3 treatment compared to L1 . Besides this, Chl a and b significantly increased, and the Chl a/b ratio significantly decreased in all treatments, while the carotenoid concentration was found decreased in the L2, L3, L4, L6, and L9 treatments compared to L1 . Similar results from a previous study described that a high ratio of both R:B and R:B:W manifested higher chlorophyll compared to natural light in Silene capitate Kom. . Each of the plant pigments has been characterized by an absorbance pattern in wavelength called the absorbance spectrum, where the blue and red regions are absorbed strongly by Chl a and b, with less absorbance of other wavelengths . It is also known that the Chl and Car pigments absorb 400– 500 nm and 630–680 nm in the light spectrum in plants with the help of light-harvesting antenna .

The positive influence of red and blue light on Chl synthesis in the present study complies with these findings . Furthermore, the accumulation of Car and the Chl a/b ratio were increased, whereas Chl b was decreased significantly under the spectra composed with green light when compared to the red and blue spectra . Since red and blue light are absorbed by photosynthetic pigments more strongly, their influence is predominant in the upper cell layers, while green light can penetrate deeper into leaf tissues and excite the photosystem in the deeper cell layer . On the other hand, Car are lipid-soluble colored pigments that mostly consist of carotenes and xanthophylls , whose absorbance range extend into the green region , effectively cover the poorest region of chlorophyll absorbance . Thus, the addition of green light along with others in the present study might increase the concentration of Car. The photochemical activity of photosystem II is expressed by Fv/Fm, which characterizes the maximum efficiency of the photochemical activity under PS II , where Fv , Fm, and F0 denotes the maximal variable fluorescence, maximal fluorescence intensity, and fluorescence intensity at 50 µs, respectively. The photosynthetic fluorescence is a byproduct of the photosynthetic process created by trapping light energy at the reaction center within a photosynthetic membrane and after being used in photochemistry that dissipates along with heat energy . A decreasing trend in Fv/Fm was observed in the treatments L1, L6, L7, and L10 in the present study . A lower Fv/Fm may be a consequence of decreasing Fm, since F0 does not change too much in light stress .Proline is an important compound as its synthesis and catabolism play an important role in the stress adaptation of plants by keeping in balance the redox reaction . Under stress conditions, ROS-mediated regulation, including H2O2, can upregulate P5CS and downregulate PRODH activity in the plant, which can trigger the biosynthesis of proline . Over biosynthesis of proline by the over expression of P5CS may play an important role in flower initiation and bolting promotion at the early stage of plant development . Lower photosynthetic pigments and fluorescence with higher accumulation of proline in the present study indicate a stress response of plants in the L1 treatment . This stress may be due to the lower intensity of natural light under greenhouse conditions. Carbohydrates are the main source of energy and are considered the main criterion of cell division activity in plants, and their concentration depends on the amount of photosynthetically active radiation . In a previous study, it was reported that UV-A light influenced the plants to accumulate more carbohydrates , whereas at a low R:FR ratio plants accumulated more soluble sugar, carbohydrates, and secondary metabolites . The ratio of red spectrum ranged from 40 to 60%, with other light sources increasing the TSC and sugar in L7, L8, L9, and L10 . The monochromatic red, blue, and their combined spectra manifested decreased soluble carbohydrate in Anthurium cut flowers in a previous study . Our present study also found a lower TSC and sucrose content in combined red-blue spectra compared to all other treatments.

From the PCA analysis, it can be revealed that both the TSC and sucrose content manifested a negative correlation with SL, LL, and LW and are closely associated with the L9 treatment. A possible explanation is based on the fact that under stress plants produce excess carbon skeletons to prevent the declining trend in photosynthetic rate and growth in plants, which help to increase osmolytes production . The reduced photosynthetic pigments , LL, and LW under the L9 treatment in the present study quite support this hypothesis. Our study found a similar pattern of TSC and sucrose content while little dissimilarities were also observed from ascorbic acid under different light spectra. It was narrated that TSC are the precursor for ascorbic acid biosynthesis, and mature green tomatoes can achieve both compounds in higher amounts under high irradiance of light, but no correlations were observed in a series of experiments between them . These results indicate that the accumulation of sucrose content and TSC is interdependent, whereas ascorbic acid is independent of both compounds. Moreover, plants accumulate all osmoprotectant molecules significantly higher when the green light was added to the other light spectra , compared to the red and blue combination . Since ancient times, wild or naturalized plants have provided social security to millions of people globally, in the form of fuel, food, fodder, supplements, raw materials for industries, medicines, and especially a source of additional income . According to the World Health Organization, about 65–80% of people in developing countries are reliant on herbal remedies made from medicinal plants . About 90% of the plant species used in the Indian herbal industry come from the Western Himalayas . The Indian Himalayan region was well-known for its floristic diversity, with approximately 1748 medicinal plant species reported from the region , which were used in various fields of chemistry, pharmacological research, pharmacognosy, and clinical therapeutic studies . Himachal Pradesh is the northeastern state of India, geographically divided into three distinct regions; the outer Himalayas , the mid-hills, and the greater Himalayas, which cover an area of 55,673 km2 . Due to its diverse climatic, topographic, and geographical position or altitude, the state of Himachal Pradesh represents a rich source of biodiversity . According to the data of the Ayurvedic Pharmacopoeia Committee , out of 1100 single-ingredient drugs, 350 plant species belong to native therapeutic groups, among which 225 species blooms in the state of Himachal Pradesh and were obtained commercially . Angiosperms, including 1003 species of dicotyledons, belonging to 498 genera and 313 species of monocotyledons, belonging to 133 genera. Whereas, the gymnosperms are characterized by only 10 species and 8 genera in the state . The contribution of dicotyledons and monocotyledons to the world flora is approximately 81.3 and 18.7 percent, respectively, trimming tray with the Shimla district accounting for 23.3 percent of monocotyledon species . Approximately 500 species of medicinal plants have been reported from Himachal Pradesh .

From the very beginning of human civilization, people have been developing their knowledge of plant use, management, and conservation . Indigenous people seem to have a hierarchical knowledge of these traditional medicinal plants for a variety of human diseases, and this knowledge has been passed on from one generation to the next . This study documents the accumulated knowledge regarding plants in the Maraog region that has traditionally been employed for the treatment of different human diseases. No such study has been conducted previously in this area, thus it will assist in providing valuable information to the ethnomedicinal research field, and such information is expected to be useful in the discovery of drugs . Such studies have been done indifferent parts of the world, including Pakistan, Nepal, Africa, America, Europe, Poland, Argentina, Australia, Iran, New Zealand, Turkey, Japan, Taiwan, Pakistan, China, Nepal, as well as different parts of South, North and East India. The declining rate of ethnomedicinal knowledge amongst younger generations was found to be a common problem in all the reported countries . As the economic condition of people living in rural areas is improving day-by-day, people are becoming less dependent on traditional medicinal practices, thus knowledge in the use of medicinal plants is also diminishing .