IN VITRO CULTURE OF PRUNUS PERSICA VAR. LAEVIS GRAY (NECTARINE): DETECTION OF BACTERIAL CONTAMINANTS AND POSSIBILITY OF DECONTAMINATION BY MEANS OF ANTIBIOTICS

The presence of non-visible epiphytic contamination was demonstrated on nectarine explants by means of different techniques: adding 88 mg/1 of yeast extract powder to the proliferation medium (PM); streaking some remnants of this medium on Petri dishes containing nutrient agar (NA); ‘imprinting’ the upper half part of the explant on to the NA.

The first technique allowed detection of only a part of the contamination at the base; the second revealed all the basal contamination and the leaf imprinting proved very efficient, showing all epiphytic bacteria of the upper half of the explant.

After screenings the explants were dipped for 1 min in three antibiotic solutions at three concentrations: streptomycin sulphate (50, 100, 200 mg/1); rifampicin (25, 50, 75 mg/1); piperacillin (50, 100, 200 mg/1) and were then cultured on PM supplemented with the same antibiotics at the same previous concentrations, or kept in PM. Other explants, without bathing, were cultured on PM supplemented with antibiotics.
The phytotoxicity and bacteriostatic activity of these compounds were investigated.
These antibiotics eliminated contaminants from only some of the cultures.
Rifampicin and streptomycin were very effective at highest rates (bath plus medium) but they exerted a strong phytotoxic activity.
Streptomycin was effective also when added in PM only.
Piperacillin had a fair capacity to suppress contaminants without phytotoxical effect.

Bacterial and Bacteria-like Contaminants of Plant Tissue Cultures

M. Scortichini, A. Chiariotti

https://doi.org/10.17660/ActaHortic.1988.225.12