Optimization of explant surface sterilization protocol for the tissue culture of Scurrula atropurpurea using combination formula NaOCl, ascorbic acid and citric acid

Benalu teh (tea parasite; Scurrula atropurpurea) is a traditional medicine that can be developed into a standardized herbal medicine. This study aims to obtain an optimal explant surface sterilization protocol for tea parasite tissue culture that is free from contamination, browning, and explant death. This research was conducted at the Plant Tissue Culture Laboratory, Muria Sari Bumi, with a completely randomized design using explants of apical shoots (nodes) and apical leaves (leaf shoots) of tea parasite. The first treatment used serial concentrations of sterile NaOCl (1.25%, 2.25%, 3.25%, 4.25%, 5.25%), whereas the second treatment used concentrations of ascorbic acid and citric acid (50 mg/1000 mg, 100 mg/1500 mg, 150 mg/2000 mg, and 200 mg/2500 mg of each). Data were analysed by analysis of variance and Tukey’s advanced test at the 5% level. The immersion with a mixture of citric and ascorbic acids yielded lower contamination (<5%) and mortality rate (<40%), and no explant browning (0%) compared to the NaOCl disinfectant in both shoots. The optimum composition of the explant surface sterilant to achieve a successful tea parasite culture was the treatment combination of 2,25 % NaOCl with ascorbic acid+citric acid in concentration of 150 mg/2000 mg. The current successful implementation of explant surface sterilization inspires its application for more complicated plant tissue culture processes.