Browsing by Author "Peiris, Sriyani E."

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An Efficient Plant Regeneration Using Leaf Explant for Osbeckia octandra (L.) DC; A Valuable Medicinal and Ornamental Plant
(Faculty of Humanities and Sciences - SLIIT, 2021-03-26) Dilrukshi, S. K.; Nagahatenna, D.S.K.; Peiris, Sriyani E.
Osbeckia octandra (Heen Bovitiya), which is one of the most valuable ayurvedic medicinal and ornamental plants in Sri Lanka is now threatened due to overexploitation in its natural habitat. In order to preserve this economically important plant species, a highly efficient in vitro clonal propagation system using leaf explants was developed in this study. The effects of three different concentrations of plant growth regulators: (6-benzylaminopurine (BAP), 1-naphthaleneacetic acid (NAA) and kinetin) and incubation conditions on plant regeneration were investigated. The plant growth parameters were analyzed in 15 biological replicates using one- way or two-way ANOVA. The present study revealed that the highest number of shoots per leaf explant with 92.4% shoot induction rate was achieved when young mature leaf explants were inoculated on Murashige and Skoog (MS) medium supplemented with 3 mg/L BAP and 0.5 mg/L NAA under dark conditions. When micro shoots were separated and subcultured on hormone-free MS medium with high sugar content (4%), shoots multiplied rapidly and a vigorous root system was developed under light conditions. The in vitro grown plantlets were successfully acclimatized and 89% of the regenerated plantlets survived. Our novel clonal propagation system will open new avenues for large- scale multiplication and improvement of medicinal and ornamental characteristics of this valuable species using biotechnological tools.
Open Access
Investi gati on of Measures to Control Epiphytes and Endophytes Present in Nodal Explants of Persea Americana Mill in Its in Vitro Establishment
(Faculty of Humanities and Sciences, SLIIT, 2024-12-04) Chamandi, S. Naveesha; Peiris, Sriyani E.
Signifi cant advancements in micropropagati on methods facilitate the commercial culti vati on of avocado (Persea americana Mill), a remarkable tropical and sub-tropical fruit, highly recommended for its nutriti onal value. Since high quality, true-to-type planti ng materials are required to promote the commercial producti on of avocado, this study was conducted with the objecti ve of investi gati ng an eff ecti ve sterilizati on method to control both epiphytes and endophytes present in nodal explants of P. americana cv. ‘Pollock’ to opti mize in vitro establishment measures which will lead to popularize its micropropagati on. In this study, nodal segments of approximately 10 cm from soft wood stem cutti ngs of P. americana cv ‘Pollock’ were used to obtain explants. The eff ects of 10%, 20%, and 30% concentrati ons of sodium hypochlorite (NaOCl) were evaluated, with exposure durati ons of 10 and 20 minutes, to determine their effi cacy in eliminati ng epiphytes during vitro establishment. Additi onally, the nodal explants were treated with 100 mg/L Augmenti n™ for 20 - minutes and 30 - minutes periods respecti vely, as a fi nal dip before culturing to eradicate endophytes. The eff ects of three diff erent culture media, half-strength Murashige and Skoog (MS) medium, Woody Plant Medium (WPM), and Gamborg’s medium (B5) were also investi gated. The highest survival rate (83%) of nodal segments was achieved when explants were sterilized with 20% Na- OCl for 20 minutes, followed by a fi nal sterilizati on step involving a 30-minute dip in Augmenti n™, and subsequently cultured in WPM medium.