Abstract
•Copper sulfate proved effective for eliminating endophytic bacteria in Philodendron selloum in vitro cultures.•Moderate level of copper sulfate did not induce growth abnormalities and was optimal for shoot multiplication of P. selloum.•RAPD molecular marker revealed genetic fidelity of the regenerated plantlets at all levels of copper sulfate.
Endophytic microorganisms is a major constrain to the establishment and growth of tissue culture plants. We report the use of copper sulfate (CuSO4.5H2O) to eliminate the endophytic bacteria in Philodendron selloum in vitro cultures. Contaminated shoots were cultured onto Murashige and Skoog (MS) medium containing 5 mg/L BA and supplemented with different concentrations of copper sulfate at 0, 35, 70 and 140 mg/L for 6 weeks. Copper sulfate at 70 mg/L completely eliminated the endogenous bacteria without decline in plant growth. However, 35 mg/L copper sulfate was optimal for maximum shoot multiplication (25), survival percentage (100%) and growth of plants. Antioxidant enzymes activity of catalase, peroxidases, and polyphenol oxidase were increased because of copper sulfate treatments. Conversely, electrolyte leakage was decreased at low copper sulfate (≤70 mg/L). Randomly amplified polymorphic DNA (RAPD) analysis revealed that plantlets exposed to different levels of copper sulfate were not genetically different from control plants.