Browsing by Author "Priyadarshan, A.I.S."

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Development of suitable propagation systems for Tephrosia spp. and Flueggea leucopyrus in Sri Lanka
(University of Kelaniya, 2013) Priyadarshan, A.I.S.; Senanayake, S.P.; Jayetilleke, M.P.; Rajapakse, R.G.S.C.
Different species of both genera Tephrosia and Flueggea are commonly used as ingredients in traditional therapeutic preparations. Due to the increasing popularity of these plants as ingredients in traditional therapeutic systems, production of planting materials for commercial cultivation is a timely requirement. This research was carried out to develop suitable propagation systems for T. purpurea, T. villosa, T. noctiflora, T. pumila and F. leucopyrus. Though Tephrosia spp. seeds have shown higher viability, low germination percentage was observed within a week on wet filter paper as well as in different six potting media. Six potting media were prepared using five raw materials namely coir dust, sand, top soil, cow dung and compost with different compositions to evaluate the seed germination and growth performance of Tephrosia species. Water impermeability of seed coats was identified as the reason for the seed dormancy in Tephroisa spp. and soaking in Con. H2SO4: H2O; 3:1 for 25 mins and rubbing on sandpaper for 2 mins were determined as suitable seed dormancy breaking methods. Variation was observed in the growth performance of Tephrosia spp. in six different potting media. Soil medium was determined as a more suitable medium compared to the hydroponic solution for all four Tephrosia species. Due to less seed production in F. leucopyrus, stem cutting propagation methods in three different potting media (Coir dust, Sand, Coir dust: Sand 1:1) were applied to evaluate the efficiency in propagation. Semi hardwood and hardwood cuttings of F. leucopyrus were well established within a period of a week in sand potting medium. These findings can be used to establish suitable propagation systems for genera Tephrosia and F. leucopyrus for commercial cultivation.
Development of Suitable Propagation Systems for Tephrosia spp. in Sri Lanka
(University of Kelaniya, 2014) Priyadarshan, A.I.S.; Senanayake, S.P.; Jayatilleke, M.P.; Rajapakse, S.
Genus Tephrosia (Fabaceae) commonly known as ‘Pila’ in Sri Lanka. Some Tephrosia spp. are used in many traditional therapeutic preparations in Sri Lanka and also in other countries. Increased use of Tephrosia in traditional therapeutic systems has developed a great demand for these species. Thus production of planting materials for commercial cultivation has become a timely requirement. Therefore, this research was conducted to determine suitable propagation systems for four selected Tephrosia spp.; T. purpurea, T. villosa, T. noctiflora and T. pumila. Even though seeds of Tephrosia spp. showed high viability, lower germination percentage was observed on wet filter paper as well as in six different potting media [M0 (Coir: dust: Sand; 1:1:1), M1 (Coir dust: Sand: Top soil; 1:1:1), M2 (Coir dust: Sand: Top soil: Compost; 1:1:1:1), M3 (Coir dust: Sand: Top soil: Compost: Cow dung; 1:1:1:1:1), M4 (Coir dust: Sand: Compost; 1:1:1), M5 (Coir dust: Sand: Top soil: Cow dung; 1:1:1:1)] during a period of one week. Water impermeability of seed coats was identified as the main reason for the seed dormancy in Tephrosia spp. and soaking seeds in Con. H2SO4: H2O; 3:1 for 25 minutes and rubbing seeds on sandpaper for 2 minutes were determined as suitable dormancy breaking methods. Variation was observed in the growth performance of Tephrosia spp. in six different potting media. Growth performances of seedlings of Tephrosia spp. in hydroponic solution and soil medium were observed and soil medium was selected as the most suitable medium for the growth of Tephrosia species based on their growth performances.
Exploring the phenetic and genetic diversity of genera Tephrosia and Flueggea (Vern:Pila) and developing effective propagation systems
(2015) Priyadarshan, A.I.S.
In vitro hardening of Dendrobium plantlets to enhance acclimatization
(Faculty of Science, University of Kelaniya, Sri Lanka, 2020) Priyadarshan, A.I.S.; Amarasinghe, V.L.P.; Panapitiya, P.D.D.M.; Leelarathne, N.D.C.S.
Orchids are one of the most important cut flowers and ornamental plants in the floriculture industry with a high commercial and medicinal value. Successful establishment of in vitro derived orchid plants under ex vitro conditions is a challenge. When transferring from in vitro to ex vitro conditions, plantlets undergo an adaptation process due to factors relating to luminosity, transpiration, photosynthesis and nutrient absorption. This limits the cultivation of some species due to high plant mortality. Paclobutrazol (PBZ) has usually enhanced orchid acclimatization by contributing to fast adaptation and high survival rates upon the reduction of transpiration, plant height, leaf area, biomass and also due to the induction of root thickness and green coloration of leaves. Therefore, this study aimed to enhance the acclimatization of in vitro derived Dendrobium cultivars by in vitro hardening process with the use of PBZ in the Murashige and Skoog (MS) medium. After 10 months of in vitro culturing, Dendrobium plantlets were subcultured in different concentrations of PBZ supplemented MS media. The experiment was completely randomized with five treatments (PBZ concentrations: 0.025; 0.05; 0.075 and 0.1 mgL−1 , and the control with no PBZ) and five replications, with three plantlets per replication. A significant dropdown of plantlet height, leaf width, root length and an increment of root diameter was observed with the enhancement of PBZ concentration in the medium when compared to the control. The lowest plantlet height (3.07 ± 0.15c cm) compared to the control (4.60 ± 0.20a cm) was observed in 0.075 mgL−1 PBZ concentration. Meanwhile, the smallest leaf width (0.45 ± 0.04b cm) compared to the control (1.23 ± 0.15a cm), the lowest root length (1.00 ± 0.02c cm) compared to the control (2.07 ± 0.21a cm), the highest root diameter (1.00 ± 0.1a cm) compared to the control (0.50 ± 0.11c cm) were observed in 0.10 mgL−1 PBZ medium. Furthermore, after the acclimatization, the survival rate of plantlets in 0.10 mgL−1 PBZ concentration has increased up to 60% with a 47% of increment compared to the control showing the highest survival rate of plantlets. According to this result, MS medium supplemented with 0.10 mgL−1 PBZ could be used as an in vitro culture medium to enhance the acclimatization of Dendrobium plantlets.
Intraspecific Variation of Flueggea leucopyrus Willd. Grown in Sri Lanka and Establishing a Suitable Propagation System
(University of Kelaniya, 2014) Priyadarshan, A.I.S.; Senanayake, S.P.; Jayatilleke, M.P.; Rajapakse, S.
Flueggea leucopyrus belongs to family Phyllanthaceae, commonly known as ‘Katupila’or ‘Heen katupila’ and has become increasingly popular as an ingredient in several traditional therapeutic systems in Sri Lanka as well as in other Asian countries. A questionnaire survey was carried out using a hundred population sample to determine the awareness of the distribution and therapeutic uses of F. leucopyrus in Sri Lanka as a preliminary survey. The aims of the present study were to interpret the phenetic variation and determine the variation of phenolic composition in leaf extracts of F. leucopyrus in different climatic zones in Sri Lanka and to develop a suitable propagation system for F. leucopyrus. Eleven floral and vegetative characters of F. leucopyrus were observed and cluster analysis was carried out to infer phenetic relationships among populations collected from localities, Colombo, Kurunegala, Puttalam and Hambanthota, .representing different climatic zones. Medicinal value of most of plants lies in phytochemicals such as phenolics, flavonoids and anthocyanidins. Thus, leaf samples were extracted into ether, and ether extracts were used to isolate phenolic compounds using 2-Dimensional paper chromatography in solvent systems, butanol: acetic acid: water; 6:7:3 and sodium formate: formic acid: water; 10:1:200. Colors of the spots were observed under UV (366nm), and Rf values were calculated. Intra specific variations were observed in the distribution of phenolics in leaves and phenetic characters of F. leucopyrus with respect to their habitats in different climatic zones. Due to low seed production in F. leucopyrus, stem cuttings (Semi-hardwood, hardwood and softwood) in three different potting media were used to evaluate the successfulness in propagation. Semi hardwood and hardwood cuttings of F. leucopyrus were well established within a period of one week in sand potting medium while softwood cutting has not responded in any of the media during the period. Medium with only coir dust was also not successful in establishing the cuttings.
Phenetic Diversity and Preliminary Phytochemical Screening of Tephrosia Pers. Spp. (Family Fabaceae) in Sri Lanka
(Ceylon Journal of Science (Biological Sciences), 2016) Priyadarshan, A.I.S.; Senanayake, S.P.; Jayatilleke, M.P.; Rajapakse, S.
Tephrosia is a genus of medicinally important perennial shrubs or herbs distributed in warm temperate and tropical regions, and belongs to Family Fabaceae. The genus is represented in Sri Lanka with 10 species. The objective of the present study was to interpret interspecific relationships of Tephrosia species in Sri Lanka using phenetic and phytochemical variations. Specimens of six different Tephrosia species including T. purpurea, T. villosa, T. noctiflora, T. tinctoria, T. maxima and T. pumila were collected from their natural habitats in different climatic zones in Sri Lanka. Sixteen floral and vegetative characters of Tephrosia spp. were observed and cluster analysis was performed to interpret phenetic relationships. Herbarium specimens were prepared and voucher specimens were submitted to the National Herbarium, Peradeniya. Phenogram indicated the presence of interspecific relationship with respect to the morphological characters. Air dried leaves were subjected to sequential solvent extractions using solvents with different polarities such as hexane, chloroform and methanol. These extracts were subjected to preliminary phytochemical screening tests to detect the occurrence of carbohydrates, protein and amino acids, glycosides, alkaloids, saponins, flavonoids, tannins, phenolics, and phytosteroids. Phytochemical screening of the different Tephrosia spp. indicated a close relationship among the species and further isolations and purifications are needed to elucidate the chemical constituents to assess the efficacy.
Phenetic variation and phenolic composition of leaves of Flueggea leucopyrus willd. (vern: Katupila) collected from different climatic zones in Sri Lanka
(University of Kelaniya, 2013) Priyadarshan, A.I.S.; Senanayake, S.P.; Jayetilleke, M.P.; Rajapakse, R.G.S.C.
Flueggea is a genus of thorny shrubs belonging to the family Euphorbiaceae, and represented by two species in Sri Lanka. Currently, Flueggea leucopyrus is becoming increasingly popular as an ingredient in several traditional therapeutic systems in Sri Lanka, as well as in other countries. According to a questionnaire survey, carried out using a population sample of hundred, the distribution of F. leucopyrus was found to be common in the dry zone, compared to the wet zone of Sri Lanka. Most of the users are of the opinion that the best ingredients for traditional therapeutic systems can be obtained from plants grown in the dry zone. Therefore, the aim of this study is to interpret the phenetic variation and determine the phenolic composition in leaf extracts and of F. leucopyrus in different climatic zones in Sri Lanka. Floral and vegetative characters of F. leucopyrus in fifteen localities in districts of Colombo, Kurunagala, Puttalam and Hambanthota were observed and cluster analysis was done. Leaf material collected from fifteen different localities were acid hydrolysed and extracted into ethyl acetate and ether. Ethyl acetate extracts were used to isolate flavonoid aglycones using cellulose Thin Layer Chromatography (TLC) plates in solvent 50% acetic acid. Ether extracts were used to isolate phenolic compounds using 2-Dimensional paper chromatography in solvent systems, butanol: acetic acid: water; 6:7:3 and sodium formate: formic acid: water; 10:1:200. Then colors of the spots were observed under UV (366nm) and Rf values were calculated. Then cluster analysis was carried out to determine the distribution pattern of flavoniod aglycones and phenolic compounds. Slight phenetic variation was observed among the different population samples. Intra specific variation can be seen in the distribution of phenolics and flavonoid aglycones in leaves of F. leucopyrus with respect to their habitats in different climatic zones. The variation observed in the specimens of different localities in the dry zone is higher than the wet zone samples. To determine the variation in the efficacy of leaves of F. leucopyrus in preparation of therapeutic systems, further elucidation of phytochemicals is needed.
Phytochemical screening and TLC profiles to identify adulteration of Osbeckia octandra (L.) (Heen bovitiya) with Osbeckia aspera and Melastoma malabathricum
(Faculty of Science, University of Kelaniya, Sri Lanka, 2020) Wijesinghe, S.R.K.S; Priyadarshan, A.I.S.
Osbeckia octandra (L.) (Heen bovitiya), which belongs to the family Melastomataceae is an endemic plant to Sri Lanka. This taxon contains different phytochemicals that have great importance in traditional therapeutic systems and widely used to treat jaundice, hepatitis and liver disorders. Lack of accurate identification and need of continuous supply of raw materials for medicinal preparations can be a cause for adulteration of O. octandra. Therefore, the present study was carried out to investigate phytochemical screening and TLC profiles of O. octandra with available adulteration materials of Osbeckia aspera and Melastoma malabathricum. Hexane, ethyl acetate, and ethanol leaf extracts were prepared using air dried leaf samples of O. octandra, O. aspera and M. malabathricum. The extracts were subjected to phytochemical screening of saponins, phenols, flavonoids and anthocyanins. These leaf extracts were separated using thin layer chromatography (TLC) technique under four solvent systems with different ratios of Hexane (HE): Ethyl acetate (EA); 9:1:17:3; 4:1 and 13:7 and three solvent systems with different ratios of Hexane: Ethyl acetate: Ethanol (ET); 18:1:1; 15:3:2 and 6:3:1 respectively. The spots were observed and retention factors (Rf) were calculated under visible light and ultra violet light (365 nm). According to the results of phytochemical screening, saponin was observed in hexane leaf extracts where phenols, flavonoids and anthocyanin were observed in ethyl acetate and ethanol extracts for all three species. TLC profiles have shown a range of Rf values of various phytochemicals in different solvent systems due to the presence of diverse groups of phytochemicals. M. malabathricum was clearly separated from O. octandra and O. aspera in TLC profile of ethanol extracts developed in solvent system of HE: EA; 13:7 under visible light. This TLC profile was observed under ultraviolet light and it has also revealed a clear difference between the phytochemical compositions of O. octandra, O. aspera and M. malabathricum. The cluster analysis of Rf values obtained from TLC profile has shown a close relationship between the phytochemical compositions of O. octandra and O. aspera. In conclusion, TLC profile obtained from ethanol leaf extracts subjected to solvent system of Hexane: Ethyl acetate; 13:7 can be used to identify adulteration of O.octandra with O. aspera and M. malabathricum.
Pollen morphometrics of family Magnoliaceae and Commelinid clade
(Faculty of Science, University of Kelaniya, Sri Lanka, 2020) Amarasiri, M.W.A.M.; Priyadarshan, A.I.S.
Basal angiosperms are classified into ANITA grade and Magnoliid clade according to the APG IV (2016) classification system. Many taxonomists have considered that some traits of the Family Magnoliaceae are independently derived (synapomorphies) from remaining Magnoliids. Commelinid clade is considered paraphyletic to the other monocots and including four orders; Arecales, Poales, Commelinales and Zingiberales. Pollen characters are potentially informative in higher-level systematics for floral evolution. Various pollen morphological features such as symmetry, shape, apertural pattern and exine configuration are considered as conservative features for the taxonomic assessments of the plants. The objective of the present investigation was to determine the phylogenetic relationships of family Magnoliaceae and Commelinid clade by studying the available species in Sri Lanka using their pollen morphometrics. Licuala grandis, Loxococcus rupicola, Fimbristylis miliacea, Cyperus melanospermus, Monochoria vaginalis, Commelina diffusa, Heliconia rostrata and Alpinia purpurata were selected as plant taxa belongs to the Commelinid clade, while Michelia champaca and Michelia nilagirica were selected from the family Magnoliaceae for the present study. The mature flowers of selected species were collected during the period of April 2019 to August 2019. Healthy anthers were separated from fresh flowers/florets. Pollens were subjected to acetolysis treatment (Acetic anhydride: conc. H2SO4; 9:1 ratio) and treated pollens were stained with Safranin (5%). Stained pollens were observed under Phase Contrast Microscope (10 x 40) and microphotographs of the pollen grains were prepared. Pollen characters were analyzed using the PAST (PAleontological STatistics) software package to interpret phylogenetic relationships. Cladogram has shown close phylogenetic relationships with family Magnoliaceae and family Arecaceae among the Commelinid clade. The studied species were aligned with the family Magnoliaceae and Commelinid clade of APG system IV (2016) with respect to their pollen morphometrics.