Abstract:
Apple (Malus domestica), is a popular fruit crop in Sri Lanka. Favourable climatic conditions for apple cultivation exist in the local upcountry region where fruit bearing trees are reported. In this study, conditions for successful in vitro establishment of apple shoot tip cultures were evaluated using juvenile shoots from field-grown plants. Initial pre treatment with a systemic fungicide (0.2% w/v Captan) prior to shoot collection and a subsequent surface disinfection procedure using a fungicide (0.05% v/v Carbendazim) and different sterillants (20% Sodium Hypochlorite/Clorox and Tween20) was performed on shoot tip and nodal explants. Surface sterilized shoots were aseptically established on Murashige and Skoog's (MS) media having 0%, 0.05%, 0.10% v/v Carbendazim, with 10 replicates each for shoot tip and 20 replicates each for nodal explants. Assessment of contamination rate and survival percentages indicated that use of MS + 0.10% v/v Carbendazim is more suitable (p < 0.05) for in vitro culture establishment. Shoot multiplication experiments were conducted using different levels (0.0,0.5,1.0,1.5 and 3.0 mgL-1) of 6-Benzylaminopurine (BAP). Out of the treatments tested, 3mgL-1 BAP is the most suitable (p < 0.05) for multiple shoot induction (4.72 + 1.71) but produces dwarf shoots. However, 1mgL-1 BAP gives the highest mean number of shoots per explant (2.39+1.91) without reducing shoot height (2.58 + 1.31 cm). While further studies on root induction and acclimatization are ongoing, the present findings indicate the possibility to use in vitro techniques for producing apple plants locally as a promising prerequisite for establishing field cultivations.
