Effects of Gamma Radiation on Growth of Sinningia speciosa Callus Tissu

Abstract

In this study, the in vitro tissue culture of the Sinningia speciosa callus was established at 25±1 ºC with light intensity 1000 μmol m-2 sec-1 and 70-80% relative humidity with a 16/8h light/dark photoperiod. Additionally, gamma radiation of 10-60 Gy was applied and the effects of gamma rays on growth of Sinningia speciosa callus tissue were investigated. A 100% callus initiation was observed in petal explants cultured on MS medium supplemented with combinations of 0.5 mg L-1 NAA and 2.0 mg L-1 BAP resulted in 100% callus induction after being cultured for 4 weeks. This medium was considered optimal medium for callus induction because it can produce normal growing healthy callus. Callus growth was based on callus weight and changing textures and colour of callus; determined following exposure of the calli to different doses of gamma rays. Results obtained indicated that callus growth was reduced when the dose of radiation was increased. It was found that increasing doses of gamma radiation (10-60 Gy) has inhibition effect on callus fresh weight on the 4-week established cultures of Sinningia speciosa callus. Gamma rays produced different effect compared to non-irradiated callus controls in morphological aspects of the callus such as textures and colour of callus cultures.