Control of microbial contamination for large-scale photoautotrophic micropropagation

Photoautotrophic (sugar-free) micropropagation has been examined for many different plant species. One of the advantages of photoautotrophic micropropagation is the low risk of contamination, which facilitates the use of large culture vessels, and thus contributes to the reduction in production cost. In this article, pathogenic and nonpathogenic contaminations are discussed, and guidelines for development of large-scale, pathogen-free, photoautotrophic micropropagation systems are introduced. A preliminary experiment was conducted for producing pathogen-free plantlets by large-scale photoautotrophic micropropagation. Addition of AgNO₃ in the medium was shown to suppress growth of nonpathogenic contaminants without reducing fresh and dry weight, and number of leaves of the tomato plantlets.