Influence of MS salts and sucrose concentrations of plant tissue culture media on the growth of bacterial contaminant in sugarcane micropropagation

Abstract

The influence of MS salts and sucrose concentrations on the growth of four strain of bacterial contaminant isolated from multiplication stage and two from the rooting stage of the sugarcane micropropagation was determined. Independent experiments were carried out with each component in Petri dishes with the media for the multiplication and rooting of in vitro plants. Treatments were elaborated with different concentrations of salts MS expressed in percentage (p/v): 0, 25.0, 50.0, 75.0, 100.0, 150.0, 200.0, as well as of Sucrose: 0, 10.0, 20.0, 30.0, 40.0g.l-1. The Petri dishes were inoculated with 3.5μl of each bacterial suspension to a final concentration of approximately 104cfu.ml-1. The growing or not of the bacterial strains was evaluated at 24, 48 and 120h of incubation at 30ºC and it was registered following the approach of: (+) growth on the inoculation place, (-) total absence of growth on the inoculation place. It was demonstrated that the salts and sucrose concentration in multiplication and rooting media of the in vitro plants limited the bacterial growth. Key Words: Bacillus, bacteria, Enterobacter, Saccharum spp. híbrido, Ochrobactrum, Stenotrophomonas