Effect of contaminants in tissue cultures of taro (Colocasia esculenta).

Abstract

Taro (Golocasia esculenta var. esculenta (L.) Schott) is easily cultured in vitro. Twenty five genetically different taro clones from the breeding program at Bubia Agriculture Research Centre, Lae, (Papua New Guinea) were cultured in vitro on modified Murashige and Skoog (MS) minimal organic medium. Endogenous contamination in taro tissue culture is not being properly acknowledged therefore this study was initiated to assess the type and rate of contamination. The rate of contamination was 56% of the total shoot tips cultured. When visually assessed, 16% of red, orange or yellow and 24% of dear or milky white coloured bacteria or yeast were observed which came out from the base of the explants. Fungal contamination on the media accounted for another 16% of the total cultures. It was shown that the presence of micro-organisms in cultures affected explants, eventually result in death when contaminated cultures were not transferred onto fresh medium. It was concluded that detection methods should be incorporated at all stages of tissue culture to avoid losses due to endogenous micro-organisms.