Abstract

Banana (Musa paradisiaca cv. Tanduk) is a high-value crop in the Malaysian market due to its versatility in food production, which necessitating large-scale seedling production via in vitro propagation. However, fungal contamination in banana culture is a major challenge that can be solved by identifying the contaminating microorganism and determining the specific sterilizing agent, antibiotic, or antifungal to inhibit its growth in the culture. Thus, this study aimed to identify the species of fungal contaminants in banana cultures originating from an oil palm-banana mixed plantation. Ethanol (70%) and sodium hypochlorite (20%) were utilized to surface-sterilize the sucker explants before inoculation in Murashige and Skoog medium. White, fluffy growth within the culture vessels was observed after four weeks, suggesting fungal contamination. The isolation of pure colonies on potato dextrose agar (PDA) was followed by polymerase chain reaction (PCR) and inter-transcribed spacer (ITS) sequencing, revealing the presence of Phlebiopsis magnicystidiata and Hypoxylon investiens. These rare fungal species are commonly found in woody plants and oil palm rhizospheres, suggesting cross-contamination from oil palm plantations (soil-borne fungi) into adjacent banana roots. This highlights a potential risk of fungal contamination during in vitro propagation. The study demonstrated the significance of microbial profiling and a targeted decontamination strategy, particularly in mixed-cropping systems, for optimizing contamination management in the banana micropropagation system.