Genus Zingiber: A review on botanical, major bioactivities and genetic diversity

Zingiberaceae is a perennial plant family that is found across the tropics, particularly in Southeast Asia from low land to hill forests. In Peninsular Malaysia, it is believed that 160 ginger species are widely distributed belonging to 18 genera. Most of the Zingiber species in Peninsular Malaysia are less investigated and less understood taxonomically, thus remaining as under-utilized crops. The description of their morphologies in parallel with phytochemicals and molecular information are crucial to provide valuable information for further discovery of potent compounds, identification of potential new sources of genetic variation, as well as to provide insight into the domestication and breeding of ginger. The majority of Zingiber species are perennial herbs with a fragrant scent, an upright stem, and a fibrous rhizome. The presence of volatile components such as monoterpenoids, sesquiterpenes, sesquiterpenoids and some non-volatile compounds like gingerols, shagaols, and zingerone have contributed to the strong scent of the ginger oils. Among the dominant components of Zingiberare α-zingiberene, geranial, neral, camphene, neral, neric acid, α-curcumene, and zerumbone. The crude extracts and essential oils of Zingiber have proven to show some biological activities such as antimicrobial, anti-bacterial, insecticidal, larvicidal, anti-cancer, anti-inflammatory, anti-ulceration, antioxidant, anti-fungal, immunomodulatory, and anti-nociceptive. Most Zingiber species are known to have 22 somatic chromosomes (2n=22) which is the lowest among genera in Zingiberaceae. This study underscores the crucial significance of breeding programs and germplasm conservation, specifically emphasizing the potential of common ginger as a prominent contributor.