Control of Contamination and Explants Phenolics in Ginger Accession (Zingiber officinale Rosc.) In Vitro Cultures

Abstract

Ginger which is an important tropical and sub-tropical herbaceous perennial plant, with the rhizome valued for its culinary and medicinal properties. In vitro growth performance of Zingiber officinale cultures is limited by contamination and phenolics. This study was aimed to minimize the effect of phenolic components and eliminate contamination for in vitro regeneration of Zingiber officinale. Our results showed that, the use of 3% (w/v) copper sulphate (CuSo₄), 0.1% (w/v) polyvinylpyrrolidone (PVP), 0.1% (w/v) ascorbic acid and 0.1% (w/v) citric acid for 6 hrs significantly reduced the sprout bud of explants browning. This pre-treatment was followed by 70% ethanol for 1 min, 1.5% (V/V) sodium hypochlorite and Tween 20 for 15 min for eliminating contaminants. Nevertheless, using whole pre-treatments browning (phenolics) were highly significant difference mean than aseptic and survival percentage. However, pre-treatments one at all periods were unable to effectively reduce contamination in bud cultures, but using 3% (w/v) copper sulphate (CuSo₄), PVP, ascorbic acid and citric acid as pre-treatment one for 6 hrs was the best for reducing contamination (33.3% clean) and browning (1.47), with a high survival rate (93.3%) on sprout bud explants. Streptomycin at 100 mg/ l was most effective against contaminating bacteria, along with the formation of the maximum number of ginger shoots, and had the least phytotoxicity. However, reduction in shoot growth and decreased rates of shoot multiplication and survivals were recorded in cultures grown on medium after the addition of 200 mg/ l of either antibiotic.

Keywords: Zingiber officinale, in vitro cultures, phenolic components, sterilization technique, copper sulphate, streptomycin.