Research Symposium-2015
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Browsing Research Symposium-2015 by Author "Alwis, L.M.H.R."
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Item Analysis of combining ability and heterosis in tomato (solanum lycopersicum) using full diallel cross(Uva Wellassa University of Sri Lanka, 2015) Jayarathna, R.G.Y.H.; Alwis, L.M.H.R.; Fonseka, H.H.; Welegama, H.M.V.T.Tomato (Solanumlycopersicum) is the second most important vegetable crop next to potato. Tomato being one of the popular vegetable crops in Sri Lanka is preferred by farmers due to high economic returns, export potentials and nutritive value. Tomato is a rich source of vitamin A, C and minerals like Ca, P and Fe (Dhaliwalet al., 2003). Tomatoes are major contributors of antioxidants such as carotenoids (especially, lycopene and β-carotene), phenolics, ascorbic acid (vitamin C) and small amounts of vitamin E in daily diets (Raiet al., 2012). In Sri Lanka, tomato is cultivated in more than 7137 ha, producing nearly 73917 t/year. (Department of Agriculture, 2010) The record lower yields are attributed to multiple of factors inclusive of elevated and frequent incidences of pest and diseases and inadequate accessibility to quality seeds (Ceylon Chamber of Commerce, 2011). Most improvement programmes of many crops use diallel analyses as they provide breeders information on the genetic value of varieties as parents and to assess the gene action which can be directed at improving yield and other related quantitative characters (Vianaet al., 2001). Therefore, an understanding of the genetic control of characters and role of non-allelic interaction is essential to the breeder when deciding of the selection method and breeding procedure to follow (Esmail, 2007). From diallel analysis, plant breeders are able to gather information on heterosis and effect due to maternal, General Combining Ability (GCA) and Specific Combining Ability (SCA) of parents in crosses (Glover et al., 2005). Materials and method Parents were obtained from the germplasm of the Plant Genetic Resource Centre (PGRC), Gannoruwa, Peradeniya.Seeds of the all possible crosses, reciprocals and Bhathiya were obtained from the Horticultural Crop Research and Development Institute (HoRDI), Gannoruwa from the maha season 2013/2014.Item Development of a protocol for in-vitro propagation of black pepper (Piper nigrum L.) local selections(Uva Wellassa University of Sri Lanka, 2015) Dissanayake, S.G.H.C.K.; Alwis, L.M.H.R.; Jayasinghe, H.A.S.L.; Attanayake, A.M.C.I.M.; Seneviratne, J.M.Black pepper (Piper nigrum L.) belongs to family Piperaceae and it is one of the most economically important spice crops in the world (Srinivasan, 2007; Mathew et al., 2001). Unavailability of sufficient mother plant stock in the field, obtaining basal runners for propagation and less success and multiplication rate of the high yielding local pepper cultivars are the major problems faced by the farmers who cultivate. Being in vitro propagation a promising option, this study was focused to develop a suitable protocol for in vitro propagation of black pepper local selections. Methodology This research was carried out at Central Research Station, Department of Export Agriculture, Matale. Four experiments were conducted during the research period. Experiment one was conducted to find out the suitable surface sterilization method for the sterilization of black pepper shoot tips. Selecting of appropriate media for the culture establishment of black pepper shoot tips were carried out in second experiment using 1/3Murashige and Skoog (MS) medium and 1/2 Woody Plant Medium (WPM).Experiment three was conducted to find out suitable combination of auxin and cytokinin for the shoot multiplication of black pepper local selections. In fourth experiment, priority was given for the selection of best media and hormonal combination for the callus initiation of TG7 black pepper local selection. Full and half strength MS media were used as the culture media and two different concentration levels of kinetin and NAA were used as the growth regulators. Complete Randomized Design (CRD) was used as the experimental design. ANOVA was used to analyze the statistical difference of parametric data and non-parametric data were subjected for logarithmic transformation. SAS statistical software was used to analyze the data and mean separation was performed using Least Significant Difference (LSD). Results and Discussion As the results summarized in Table 1, sterilization using 10%- 20% Clorox for five to ten minutes (T1 to T5) showed higher percentages of bacterial contamination (40 to 80 %). Lower percentages of fungal contamination was observed in T4 to T8 within the period of three to five days (3% to 7%).The highest survival percentage (66.6 %) was reported in T8, 0.04 % HgCl2 for five minutes. Similarly, the lowest percentages of bacterial and fungal contamination were observed in T8. The highest percentage of phenolic browning (80%) was shown in T6 and lowest percentage of phenolic browning (10.0%) was observed in T2, i.e. 10% Clorox for 10 minutes within four to seven days.Item Feasibility study for direct planting of in vitro potato (Solanum tuberosum L.) varieties Granola and Golden Star in aeroponic system(Uva Wellassa University of Sri Lanka, 2015) Wijesinghe, A.P.; Alwis, L.M.H.R.; Jayasinghe, H.A.S.L.; Nugaliyadda, M.M.The major constraints in potato cultivation are high seed cost, poor seed quality, unavailability of quality seeds at correct time for planting, frequent application of fungicides to control late blight disease, misappropriation of agrochemicals and limitation of suitable land. The total seed potato requirement in Sri Lanka is about 22,500mt per annum. Total annual importation of seed potato is about 7000mt and the Department of Agriculture produces about 400mt of high generation seed potato per annum. The rest of the seed potato requirement of about 60% is fulfilled by farmers own seed production. Seed potatoes are the most costly input having 53% of the total cost of production.Main objective is to study the feasibility of direct planting of Granola and Golden star in vitro plants in aeroponic system. Other objective is to identify the suitable liquid media for hardening of in vitro potato plants. Materials and method The planting materials which were used in research are In vitro potato plants, MS media, Albert solution and aeroponic system. First culture media was prepared for in vitro potato plants. Stock solution was measured to prepare MS medium. Then 0.1g of myo-inositol, 30g of sugar, 1g of charcoal and 9g of agar were measured and mixed well. Solution was diluted up to the 1l. pH was measured and adjusted up to 5.75. Culture bottles were filled by solution up to 30ml. Bottles were allowed for settle.In vitro plants were cut with node and cuttings were placed in culture bottles. Then bottles were labeled and placed in the culture room. Cultured bottles were kept for one month period. Half MS, full MS and Albert solution were prepared. pH was measured in MS solutions and adjusted to 5.75. Electrical conductivity was adjusted up to 1.7 in Albert solution. Six treatments were taken. (Golden star in 1/2 MS medium as treatment 1, golden star in MS medium as treatment 2, golden star in Albert solution as treatment 3, granola in 1/2 MS medium as treatment 4, granola in MS medium as treatment 5, granola in Albert solution as treatment 6) Data were collected at one week intervals. Mean shoot length, mean root length and mean number of roots were taken as the parameters. (In this research increment of growth was measured for each parameters) Albert solution was prepared for 250l of tank (EC-1.643 ms/cm). Electrical conductivity was adjusted up to the range of 1.5 to 2.0 ms/cm. Acclimatized plants were dipped in Thiram (2g/l). Then plants were placed in aeroponic system. Aeroponic system was adjusted to spray five second with once in five minutes at day time and once in fifteen minutes at night in first three days. Next four days system was adjusted once in ten minutes at day time and once in twenty minutes at night. After that system was adjusted once in twenty minute at day time and once in thirty minutes at night. EC was checked every day. Data were collected at weekly for seven weeks. Mean shoot length, mean root length, mean stolen length, mean number of stolen and mean number of tubers were taken as the parameters. (In this research increment of growth was measured for each parameters) Results and Discussion In both experiments collected data were analyzed by using minitab 16 under general linear model. According to the Table 1, the highest shoot length growth (3.13cm) was observed in variety Golden star with Albert solution (T3). Others are statistically different, but T6, T1 and T3 are comparable. Though T2, T4 and T5 are comparable but significantly lower than T3. When comparing mean length of root growth, there is no significant different in each treatment. Number of root increment are statistically significant each other. Therefore using of any treatment is not largely effect on root number or root length.