Efficiency of Ampicillin in Contamination Control and in vitro Growth Response of Three Ginger Morphotypes (Zingiber officinale Rosc) of Benin

Abstract

Establishing an aseptic culture remains a critical step in in vitro culture, particularly when explants originate from the underground organs of field-grown plants, such as ginger (Zingiber officinale Rosc.). The efficiency of ampicillin in contamination control and its influence on the in vitro regeneration response were tested in combination with sodium hypochlorite (NaOCl) and/or mercuric chloride (HgCl₂) using three ginger morphotypes of Benin. Ten explants per morphotype were cultured for each treatment, with three independent replicates. Explant contamination was significantly influenced by the use of 0.2% ampicillin in combination with NaOCl and/or HgCl₂, as well as by ginger morphotype (p < 0.05). However, ampicillin did not significantly affect explant survival, regeneration rate, or days to first shoot emergence (DAPP) in the three ginger morphotypes (p > 0.05). In contrast, morphotype had a highly significant effect on regeneration and shoot emergence time (p < 0.0001). The addition of ampicillin to the disinfecting agents reduced explant contamination, with the combination of NaOCl + HgCl₂ + ampicillin resulting in the lowest contamination rates across the three morphotypes W, Y, and D (18.52%, 18.52%, and 7.41%, respectively). The giant fibrous yellow-fleshed morphotype (D) showed the highest survival and regeneration rates, reaching 90.0 ± 2.3% and 75.0 ± 3.1%, respectively, whereas the yellow-fleshed morphotype (Y) exhibited the lowest performance, with survival and regeneration rates as low as 5.0 ± 0.5% and 5.0 ± 1.3%, respectively. In contrast, Y showed the earliest shoot emergence (5.2 ± 2.1 days), whereas D had the longest emergence time (10.10 ± 2.1 days). These findings provide an optimised disinfection protocol for the rapid production of high-quality planting material.