Effects of Silver Nitrate in In Vitro Establishment of Cordyline fruticosa (L.) cv ‘Purple Compacta Tri Colour’ with CSUP Media Sterilization

Abstract

Cordyline Varieties have gained high interest in the export markets for the in vitro ex agar plant material. Though in vitro plants have many advantages in export markets required quantities cannot be produced in a given period of time due to the high contamination rates in establishment of explants. Hence, this study was carried out to investigate silver nitrate (AgNO3) in three concentrations, on Cordyline fruticosa cv ‘Purple Compacta Tri Colour’ as an efficient chemical which can overcome contaminations occurring during introduction of explants to the in vitro environment. Actively growing shoot tips and nodal explants from 6 cm below from the shoot tip of C. fruticosa were selected as explants. Surface sterilization of these explants was carried out with silver nitrate in three concentrations, 0.025%, 0.05% and 0.1%. Clorox™ in 10% was used as the control. The explants were cultured in Murashige and Skoog (MS) medium, with 0.5mg/L benzyl amino purine (BAP), which was sterilized with CSUP media sterilization. Data of non-contaminated cultures was collected after three weeks and shoot growth from explants was recorded after two months. According to the results obtained the explants treated with 10% Clorox™, 0.025%, 0.05% and 0.01 % of AgNO3 had 13, 17, 22 and 40% uncontaminated cultures, respectively. These survived explants produced shoots in 50, 50, 60 and 66 % of uncontaminated explains, respectively after 2 months in the same medium. The production of uncontaminated cultures was significantly (P=0.001) different from the other two concentrations used and the control. The shoot production was not significantly affected by the AgNO3 levels and when compared with the control. Hence, it can be concluded that 0.1 % of Silver Nitrate is an efficient chemical to obtain high amount of axenic cultures and shoots, in CSUP sterilized medium, which can be used for multiplication in vitro.