Contamination Control of In Vitro Cultures of Passiflora Species for Multiplication Purpose

Abstract

This study was conducted to obtain biological material regenerated from Passiflora caerulea and Passiflora quadrangularis by direct and indirect organogenesis, in order to enrich the assortment of flowering plants in Romania. The endogenous latent contamination of the plant material used for in vitro culture initiation is one of the biggest problems, demanding a special approach. The explants disinfection steps was organized as a trifactorial experience which included two variants of NaOCl concentrations (0, 5%, 10%), three immersion times in the sterilizing solution (10, 15 and 20 minutes) and the four types of explants (apical buds, fragments of young and mature leaves, and flower explants represented by pedicel, receptacle and sepals) taken from mature plants, in the stage of active growth. The explants were pretreated with 70% EtOH solution with a few drops of Tween 20, for 1 minute, and rinsed with distilled water, then disinfected according to the experimental variants. The explants were initiated on Murashige and Skoog, (1962) medium in order to stabilize the culture. The leaves explants reacted best to the treatment with 5% hypochlorite for 15 minutes. P. caerulea registered an average contamination rate of 52.78%, lower than P. quadrangularis in which case the explants obtained an average contamination rate of 58.24%.