Browsing by Author "Lakmali, G. B. T."

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Alternative gelling agents to develop cost effective medium for in vitro propagation of Dendrobium cv. “Big Jumbo White”
(Faculty of Science, University of Kelaniya Sri Lanka, 2022) Kanishka, W. S.; Lakmali, G. B. T.; Umesha, M. S. P.; Priyadarshan, A. I. S.; Senanayake, S. P.
In vitro propagation is the most common method of Dendrobium propagation. Commonly, agar is used as an effective gelling agent though, it is expensive. However, the developing a cost-effective method is beneficial for small-batch productions and is recommended. The objective of the current study was to evaluate the efficacy of ‘kithul’ flour (starch extracted from the pith of Caryota urens) and xanthan gum as alternative gelling agents to develop an efficient, cost-effective medium for in vitro propagation of Dendrobium. Seeds of Dendrobium cv. “Big Jumbo White” was cultured using full-strength Murashige and Skoog (MS) medium. After 90 days of incubation, 1g of Protocorm Like Bodies (PLBs) and plantlets of Dendrobium cv. “Big Jumbo White” were transferred to twelve different MS media supplemented with BAP (Benzyl Amino Purine) (2.5 mg/L) and NAA (Naphthalene Acetic Acid) (0.5 mg/L) and solidified with either agar (1:0) or with alternative agents; kithul flour (0:1) and xanthan gum (0:1) or a series of combinations of each alternative gelling agent with agar (1:4, 2:3, 3:2 and 4:1) totalling to 12 treatments with six number of replicates per each. The weight of plantlets and PLBs, number of plantlets, number of leaves, number of roots, and length of the roots were recorded as growth parameters in fortnight intervals for a period of 90 days to assess the growth performance. After 90 days of incubation, the MS medium of agar: kithul flour (1:4) of the treatment series with kithul flour and agar: xanthan gum (2:3) of the treatment series of xanthan gum, have shown significantly high performance in the growth and development of PLBs and plantlets. Four growth parameters, number of plantlets: 44, number of leaves per plantlet: 5, number of roots per plantlet: 12 and root length: 1.5 cm, were significantly high in the agar: kithul flour (1:4) medium than in the agar: xanthan gum (2:3) medium. Moreover, compared to the conventional tissue culture media prepared using only agar, the modified medium using agar: kithul flour (1:4) has shown 73% of cost reduction. In conclusion, the use of agar and kithul flour (1:4) as an alternative gelling agent can be recommended as a cost-effective medium for the development of PLBs into plantlets of Dendrobium cv. “Big Jumbo White” on a small scale in vitro culture system.
Sea moss as an alternative gelling agent to develop a cost-effective in vitro culture medium for the propagation of Phalaenopsis cv. Pink lip
(Faculty of Science, University of Kelaniya Sri Lanka, 2023) Wishwakulathil, D. T.; Priyadarshan, A. I. S.; Senanayake, S. P.; Lakmali, G. B. T.
Genus Phalaenopsis is an ornamental orchid with the greatest commercial importance in the world floriculture industry. The propagation of Phalaenopsis is difficult by conventional breeding due to delayed flowering and uneven characteristics of flowers. Therefore, conventional Phalaenopsis cultivation is ineffective for large-scale production. At present, the tissue culture technique is extensively used for the mass propagation of Phalaenopsis. Tissue-cultured plants are more expensive than traditionally propagated plants due to the high cost of the chemicals used for the preparation of tissue culture media. Agar is widely used as a gelling agent and the most expensive ingredient in the preparation of tissue culture media. Developing a cost-effective invitro culture media using low-cost components is one strategy to reduce the production costs of tissue-cultured plants. The use of alternative gelling agents to replace the agar can highly contribute to reducing the cost of in-vitro culture media in tissue culture than other components. The main component of sea moss is carrageenan, a gelatinous substance used to thicken or as a solidifying agent. The ability of carrageenan-based hydrogels to produce thermos-reversible gels and viscous solutions makes them a desirable option for extensive use as a gelling agent. The objective of the present research was to assess the performance of sea moss as an alternative gelling agent to determine the effectiveness for in vitro propagation of Protocrom-like bodies (PLBs) of Phalaenopsis cv. Pink lip. Growth performance of PLBs of Phalaenopsis cv. Pink lip was used to assess the effect of sea moss as an alternative gelling agent. PLBs (0.020g) were transferred to ½ MS medium containing agar as a gelling agent, and ½ MS medium containing sea moss as a gelling agent. Cultures were maintained for four months and the growth performance of PLBs was evaluated, with fresh weight as a parameter at 30 days intervals. There was no significant difference observed in the mean fresh weight of PLBs throughout the fourmonth period, incubation in ½ MS medium containing agar, and medium containing sea moss as an alternative gelling agent. Moreover, there was no significant difference between the contamination percentages of the agar-containing medium and sea moss-containing medium. According to the cost calculation, the cost reduction resulting in the medium with sea moss as an alternative gelling agent was 79.81% compared to the conventional agar as the gelling agent. In conclusion, the application of sea moss as a gelling agent in tissue culture media can be utilized to achieve the optimum benefits for in vitro propagation of PLBs of Phalaenopsis cv. Pink lip. Based on the findings, sea moss can be recommended as a cost-effective alternative gelling agent for the propagation of Phalaenopsis cv. Pink lip using protocorm-like bodies.
Sea mosses as an alternative solidifying agent for in vitro micropropagation of Dendrobium cv. “Big Jumbo White"
(Faculty of Science, University of Kelaniya Sri Lanka, 2023) Lakmali, G. B. T.; Priyadarshan, A. I. S.; Senanayake, R. A. S. P.
Agar is a commonly added agar is not used as a gelling agent but as a solidifying agent to culture media as solidifying agent. However, agar is an expensive ingredient in the preparation of in vitro media and finding alternative sources as solidifying agents would be beneficial to small scale tissue culture production. Sea moss derived from algal species would be a potential source for serving as gelling agent. Therefore, the present study was conducted with the objective of developing a cost-effective in vitro medium for micropropagation of Dendrobium cv. “Big Jumbo White” using sea moss as an alternative gelling agent. Seeds of Dendrobium cv. “Big Jumbo White” were cultured using full-strength of Murashige and Skoog (MS) basal medium for 45 days under in vitro conditions. The initiated Protocorm Like Bodies (PLBs) were separated and used to assess the effectiveness of agar and sea moss as gelling agent on organogenesis. Media series, supplemented with plant growth regulators (PGRs); BAP (2.0 mg/L) and NAA (0.5 mg/L), sea moss; 4.5g/L (T1), 7.0 g/L (T2), 9.5 g/L (T3), 12.0 g/L (T4), 14.5 g/L T5, and agar as conventional gelling agent [8g/L (T6)]. After 60 days of incubation 1g of PLBs were placed to produce plantlets of Dendrobium cv. “Big Jumbo White”, then were transferred to six different MS media. Agar (8g/L) was used as the control. The highest shoot regeneration (12 cm) was observed in the MS medium containing 12g/L of sea moss. The data were analyzed using the ANOVA and there was no significant difference between sea moss (12g/L) gelling agent and agar (8g/L). According to the findings, MS medium containing sea moss as the gelling agent was successful in the regeneration of shoots from seed culturing of Dendrobium cv. “Big White Jumbo”. Furthermore, in vitro tissue culture media prepared using sea moss compared with agar has shown a 81 % of cost reduction. In conclusion, sea moss can be recommended as a suitable gelling agent for in vitro shoot generation of Dendrobium cv. “Big Jumbo White”.