Abstract:The ability of in vitro micropropagtion to produce high quality planting material in large quantities is hindered by their high cost of production. Hence the price of planting material is high, making them unaffordable to growers. However, a larger portion of the capital and running cost of micropropagation can be reduced using CSUP (pronounced as seesap) technique, where sodium hypochlorite is used to sterilize glassware and culture media followed by culturing without using a laminar flow cabinet. This study was undertaken with the objective of evaluating the feasibility of the CSUP technique to replace the sterilization carried out using autoclaves and laminar flow cabinets.Sodium hypochlorite in four concentrations 5, 10, 15 and 20% (v/v) were used to rinse glassware and accessories prior to pouring the appropriate culture medium for anthurium cv 'Tropical Red' in vitro shoot multiplication. The culturing of axenic shoots was carried out inside a glass-cage and cultures were placed in the growth room. Autoclaved culture medium and a laminar flow cabinet were used in the case of the control cultures. Results revealed that the percentage of contaminationfree cultures, dry weight increase and the shoot multiplication were not significantly different between the respective treatments and the controls, as well as among treatments of different sodium hypochlorite concentrations. Therefore, the CSUP technique using 5% (v/v) sodium hypochlorite solution can be adopted to replace the use of an autoclave and the laminar flow cabinet in the major micropropagation activity of in vitro multiplication.

Bael (Aegle marmelos (L.) Corr.) is a medicinal fruit tree species belongs to the family Rutaceae grown in South Asian countries including India, Sri Lanka and Bangladesh. It is an underutilized fruit species in Sri Lanka, although it has food as well as medicinal value with a good economic potential. Popularizing bael as a profitable cash crop is often hindered by the limited availability of high quality planting material. In Sri Lanka, five elite bael accessions namely Beheth Beli, Paragammana, Mawanella, Rambukkana and Polonnaruwa Supun have been identified and used for mass propagation through budding and grafting. But this effort is often hampered by many limitations faced in large scale production. Micropropagation is an alternative technique to produce clonal plants in large scale. However, the complex phenological behaviour of the bael trees could affect its success. Therefore, the present study was undertaken to identify the correct phenological stage of bael trees to collect explants for the micropropagation. Leaves and twig explants were collected for micropropagation from five elite bael accessions during the period of July, 2016 to June, 2017 on monthly basis to capture the best phenological stage. The Beheth Beli tree and grafted plants of other four accessions were established at the Fruit Crop Research and Development Institute, Department of Agriculture, Sri Lanka. The surface sterilized explants were established on Murashige and Skoog medium supplemented with 1 mg/L of 6-Benzylaminopurine, 3% sucrose, solidified with phytogel. A successful organogenesis was only observed in explants collected in the months of April, May and June (39 to 68 %) where there was no significant difference in success was observed between the leaf and twig explants (P>0.05). However, grafted bael accessions exhibited a significantly different mean success percentage in organogenesis where Paragammana and Rambukkana accessions showed a high success for leaf explants and Mawanella and Rambukkana accessions showed a high success for twig explants. These results could be readily employed to multiply the elite bael accessions in Sri Lanka.