Bacterial and Fungal Contamination during Garlic (Allium sativum L.) Initiation in In Vitro Culture

Problems of bacterial and fungal contamination during the introduction of garlic (Allium sativum l.) Into in vitroculture

Abstract

The present study investigated bacterial and fungal contamination occurring during the establishment of garlic (Allium sativum L.) in vitro cultures. The aim of the study was to assess the level of contamination in explants and evaluate the effectiveness of standard surface sterilization protocols. The scientific novelty of the study lies in the first comprehensive assessment in Kazakhstan of bacterial and fungal contamination occurring during the establishment of garlic in vitro cultures. The experiments demonstrated that conventional sterilization methods, including ethanol and disinfectant treatments, did not ensure complete decontamination of the plant material. Consequently, microbial contamination was observed at the early stages of cultivation, resulting in partial or complete necrosis of explants and reduced efficiency of micropropagation. The degree of contamination varied among garlic cultivars, suggesting an influence of genotype and the physiological condition of the donor plants. Microscopic analysis indicated the predominance of fungal morphotypes consistent with genera such as Fusarium, Penicillium, and Aspergillus, as well as the presence of diverse bacterial microflora. However, accurate taxonomic identification of the contaminants requires further molecular genetic analysis. The results demonstrate that microbial contamination remains a critical limiting factor for the successful establishment of garlic in vitro cultures. Therefore, improved pre-treatment of plant material, optimization of sterilization protocols, and refinement of culture conditions are required. The practical significance of the study lies in the development of more effective approaches to reducing contamination, thereby increasing the success rate of micropropagation and facilitating the establishment of healthy in vitro collections.