ICAPS 2020
Permanent URI for this collectionhttp://repository.kln.ac.lk/handle/123456789/21780
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Item 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.Item 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.Item 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.