Reduction of bacterial manifestation in the in vitro cultivation of Eucalyptus microcorys F. Muell

Abstract

Micropropagation is one of the main applications used for tissue culture of plants. It allows rejuvenation and, consequently, improves explant rooting of woody species. However, one of its main problems is the risk of microbial manifestation. Here, we aimed to evaluate the survival and the reduction in bacterial manifestations on in vitro cultures of Eucalyptus microcorys with the supplementation of chemical agents (sodium hypochlorite or streptomycin) to WPM culture medium. We used in vitro cultivated explants from adventitious shoots of two E. microcorys selected plants, over at 44 years-old. We drew from the multiplication phase explants with 8–12 shoots that displayed bacterial manifestation and subjected them to microbe control. We added different chemical agents at different concentrations to the culture medium: sodium hypochlorite (NaOCl) and the antibiotic streptomycin. The results indicated that the best concentrations to reduce the manifestation of microorganisms during in vitro cultivation were 100 mg L−1 of streptomycin and sodium hypochlorite with 0.003% of active chlorine, since these concentrations maintained 100% survival of the explants and reduced bacterial manifestation more efficiently.