Cefixime manages internal bacterial contamination during tissue culture operation

Abstract

Large-scale propagation of Pyrus communis, which is a difficult-to-root species, is dependent on tissue culture technique. However, internal bacterial contaminations are an obstacle in tissue culture of fruit tree species. For this purpose, this investigation was conducted with several experiments to manage bacterial contamination. First, gram test for bacterial contamination related to Pyrus shoots proliferating was conducted. Gram test revealed that bacteria contaminating pear shoots were negative gram. Then, we investigated the application of cefixime (0, 100, 300 and 500 mg L^-1) or ampicillin (0, 100, 300 and 500 mg L^-1) for managing bacterial contaminations. It was found that the contaminated area on medium containing 500 mg L^-1 cefixime (63.585 mm²) was lower than other treatments (803.84 mm²). Therefore, cefixime at 500 mg L^-1 was selected to control the bacterial contamination. Next, different procedures were used included shaking with (1: sterile distilled water, 2: 500 mg L^-1 cefixime and culturing in media with 500 mg L^-1 cefixime, 3: 500 mg L^-1 cefixime, culturing and subculturing in media with 500 mg L^-1 cefixime 4: Disinfection). The third procedure was known the best due to the low bacterial contamination percentage and rate also the healthy growth of plants. Finally, the effect of gibberellic acid at 0 and 1 mg L^-1 was investigated to compensate for shoot growth reducing in the presence of cefixime. 1 mg L^-1 gibberellic acid improved the growth indices in the presence of cefixime