Research Symposium-2016

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Browsing Research Symposium-2016 by Subject "Aquatic Plant"

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    Determination of a Suitable Hardening Medium for Micropropagated Anubias nana
    (Uva Wellassa University of Sri Lanka, 2016) Kumari, A.M.S.M.; Jayamanne, S.C.; Chandrarathna, W.P.R.
    Most of aquatic plant varieties are used in aquariums as ornamental plants due to their aesthetic and ecological value. The genus Anubias of the family Araceae is considered as one of the highly demanded plant types among other aquatic plant species. Among Anubias varieties, A. barteri var. nana is considered as a most cultivated and commercially important species. Micropropagation is currently applied to this plant as a tool for large scale multiplication of plants since the planting material has a very low multiplication rate. However, the high rate of mortality experienced by micro propagated plants during or following laboratory to outdoor transfer is still existing as a major limitation in large scale applications. Therefore, it is a requirement to develop an effective acclimatization procedure for a successful establishment and survival of plantlets. The present experiment was carried out in order to determine a suitable hardening medium for micropropagated Anubias nana using complete randomized design. The study was conducted at the Ornamental Fish Breeding and Training Centre, Rambadagalle. Four weeks old uniform sample of in vitro rooted Anubias nana plantlets were hardened by using five different potting media. Coir dust, coconut husks, clay brick shards, boggy soil and sand were used as different hardening media/treatments. Each treatment was replicated ten times. Every plantlet was provided with a constant amount (N: P: K-4:2: 1) of a commercial fertilizer in once a week. The performances of plantlets were measured by using survival rate and growth in each treatment. The measured growth parameters were number of roots and leaves, length of roots and leaves, fresh weight and dry weight of plantlets after 6 weeks of hardening period. Data were analyzed by using one way ANOVA and Tukey's test. The maximum survival percentage (100%) was obtained in coir dust, clay brick shards and sand. Out of five treatments of media, a significant difference (p<0.05) of root growth was shown by plantlets in coconut coir dust and sand. A significant difference (p<0.05) of leaf growth and weight was reported in plantlets in clay brick shards media. Keywords: Anubias nana, Micropropagation, Hardening
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    Study of the Diversity of Benthic Macro-Invertebrates at Panadura Estuary in Sri Lanka
    (Uva Wellassa University of Sri Lanka, 2016) Weerasooriyagedara, M.S.; Hettige, N.D.; Amarathunga, A.A.D.; Rajapaksha, R.M.G.N.; Jayamanne, S.C.; Weerasekara, K.A.W.S.; Maddumage, M.D.S.R.; Azmy, S.A.M.; Wickramaarachchi, W.D.N.; Jayawardane, J.K.P.C.; Narangoda, S.R.C.N.K.
    Panadura estuary situated in the western province in Sri Lanka where Bolgoda lake opens into Indian Ocean harbours a lot of aquatic biodiversity. Therefore, main objective of this study was to identify the diversity of benthic macro-invertebrates, to assess the correlation between physico-chemical parameters and macro-benthic invertebrate diversity and to evaluate the pollution level in the estuary with respect to the diversity of benthic macro-invertebrates in Panadyra estuary. Both sediment and bottom water samples were obtained from 19 randomly selected sampling locations in Panadura estuary. Collected Benthic macro-invertebrate samples were wet sieved and identified using standard identification keys. The diversity of benthic macro — invertebrates was determined by using Shannon —Weiner index, richness was calculated using Margalef s index and the health status of the estuary was determined by using Pollution Tolerance Index. Similarities among macro-benthic communities at different locations were determined by using Bray — Curtis similarity coefficient. This study also attempted to determine the physico — chemical determinants that govern the spatial variation. Individuals of 1708 species of macro benthos belonging to 14 families were identified. Planobidae, Haminoidae and Veneridae were the most abundant families. The lowest species richness and diversity was reported at PE6 while highest species richness and diversity was reported at PE7. The sampling locations were separated into several clusters based on the diversity of macro benthos. The major physico-chemical parameters which had effect on the diversity of macro benthos were Biochemical oxygen demand and nitrate nitrogen concentration. Shannon Weiner diversity index in each location at Panadura estuary was in between 2 — 3 and Pollution Tolerance Index in each location was lower than 20. Both these indices confirmed that the aquatic health of Panadyra estuary was in poor condition. Key words: Benthic macro- invertebrates, Diversity, Pollution Acknowledgements: The authors are thankful to the National Aquatic Resources Research and Development Agency for providing funds to carry out this research project