Volatile profiling of aromatic African ginger (Siphonochilus aethiopicus) in response to irrigation regimes and nitrogen levels

This study assessed the volatile organic compounds of different parts of Siphonochilus aethiopicus in response to water regimes and nitrogen levels. Gas chromatography/mass spectrometry was used for volatile analysis. A total of 35 volatile organic compounds were detected in the rhizome, 33 in the leaf and 28 in the root. The compounds were characterized according to eight chemical classes. The most abundant compounds in the root and rhizome were terpenes, as compared to the increased concentrations of aliphatic acids, benzenoids and aliphatic aldehydes in the leaf. The odorant sesquiterpene (1E)-5-methyl-1-(2, 6, 6-trimethyl-2, 4-cyclohexadien-1-yl)-1, 4-hexadien-3-one was emitted in the rhizome (64.50%), leaf (21.35%), and root (13.73%) in higher amounts. Although 4-hydroxy-4-methyl-2-pentanone (9.49%) was detected in all plant parts and the concentration increased in the root for the severely stressed treatment. Low content of Linalool was obtained in the rhizome (9.09%) and root (8.29%) grown without N application under severe water stressed treatment. The concentration of terpenes in all plant parts was increased in response to severely water-stressed treatment. Water stress and mineral nutrient deficiency provide a useful guide for selection toward of volatile components in different parts of S. aethiopicus for the additional value of pharmacological properties.