Karyotype and Phytochemical Analysis of Four Zingiberaceae Species and Their Taxonomic Relevance in Systematic Botany

Herbaceous plants in the Zingiberaceae family that grow in humid tropical and subtropical regions are economically used as dyes, ornamental plants, flavoring and spices. This study evaluated the phytochemical and karyotype components of four Zingiberaceae species in order to determine their taxonomic relationships for methodical analysis. The karyotype analysis of the studied Zingiberaceae species was based on chromosome pair, type, and length, whereas, the phytochemicals of the samples methanolic extracts were identified using gas chromatography mass spectrometry (GCMS). The karyotype analysis reveals that the chromosomes indicated similar types and comparable lengths at different pairs, for instance, Z. officinale indicated (3 submetacentric, 1 metacentric and 3 subtelocentric); E. cardamomum indicated (3 submetacentric, 2 metacentric and 2 subtelocentric); C. longa indicated 4 subtelocentric and 3 submetacentric) while A. meleguata showed 2 submetacentric, 4 subtelocentric and 1 metacentric). The GC-MS analysis on the methanolic extracts of the four test samples revealed the presence of twelve (12) compounds in Zingiber officinale, twenty-one (21) compounds in Elettaria cardamomum, seventeen (17) compounds in Curcuma longa, and thirteen (13) compounds in Aframomum melegueta. The identified phytochemicals comprise Zingerone, Oleic acid, Eucalyptol, α-Tumerone, and gamma-Sitosterol, among others, which are utilized in various pharmaceutical applications. The four chosen Zingibereceae plants demonstrated commonalities in their phytochemical profiles, specifically in the presence of terpenes and fatty acids. These results indicate that both the phytochemical compositions and karyotype characteristics of plant species ought to be taken into account when classifying plant families taxonomically. However, there is the need for more taxonomic studies using other lines of taxonomic studies.