E. I. Eziashi, O. Asemota, C. O. Okwuagwu, C. R. Eke, N. I. Chidi and E. A. Oruade-Dimaro
The demand for oil palm tissue culture seedlings is on the increase. The use of oil palm as a source of explants material for the production of clean in vitro plantlets to meet the demand, presents a major challenge of endophytic bacterial contamination. To avoid contamination from explants before being used in plant tissue culture, different sterilizing agents were used. The best for surface sterilization was 50% Chlorox plus 0.1% mecuric chloride with 6% contaminants, followed by 50% chlorox (7.5%), 0.1% Mecuric chloride (12.0%) and 70% Ethanol (27%). Color browning of the explants was noticed. Sterile distilled water was less supported with 85%. Six types of bacterial species were isolated from the explants inoculated in the medium without antibiotics. These were Proteus vulgarius, Bacillus subtilis, Pseudomonas flourescens. Erwinia sp., Staphylococcus aureus and Corynebacterium sp. Seven antibiotics were evaluated to determine their potentials to inhibit these bacterial species. Antibiotics such as Gentamycin and Ampicilin best supported inhibition of mycelial growths with 90% each. These were followed by Streptomycin with 80%, Rifampicin (80%), Tetracycline (60%), Cefotaxime (55%), Penicillin (45%) and Sterile distilled water (10%) ten days after incubation in antibiotics Nutrient agar medium. The poor performance of surface sterilization using sterile distilled water was an indication that, the host plant was a source of bacterial contaminants. This study has shown that some bacteria survived surface sterilization of oil palm explants before being used for tissue culture.
