Leaf epidermal micromorphology of Zingiber (Zingiberaceae) from China and its systematic significance

Abstract

Leaf epidermal characteristics are important for phylogenetic and taxonomic studies of many plants, but there is currently insufficient such data for this application in Zingiber species. Therefore, the leaf epidermal micromorphology of 22 species in three sections of Zingiber was investigated by light microscopy and scanning electron microscopy. Differences between various taxonomic groups of Zingiberaceae were also compared to assess their phylogenetic and taxonomic significance. As in other genera of Zingiberaceae, the epidermal cells in both the adaxial and abaxial epidermis of Zingiber species were found to be hexagonal or polygonal, with non-sinuous anticlinal walls that are arranged parallel to leaf veins. Tetracytic stomata are mostly randomly distributed in the intercostal regions of both surfaces and are more common on the abaxial surface. The stomatal density of the species in sect. Pleuranthesis is significantly lower than that in sects. Zingiber and Cryptanthium. There are two types of trichome in Zingiber: so-called “delicate” trichomes are present in most species, while “stout” trichomes with a swollen base are only found in Z. corallinum and Z. montanum. Oil cells occur in both epidermal layers of some species in sects. Zingiber and Cryptanthium, but only in the abaxial epidermis of Z. ellipticum in sect. Pleuranthesis. Crystals are found in the abaxial epidermis only in all species, but are present in both epidermal layers of Z. corallinum and Z. montanum. Although the epidermal morphology is similar in most Zingiber species, stomatal density, type of trichome and distribution of oil cells and crystals offer valuable information for the systematic and taxonomic studies in this genus.

Morphological characters, pharmacognostical parameters, and preliminary phytochemical screening of Curcuma sahuynhensis Škorni?k. & N.S.Lý in Quang Ngai Province, Vietnam

“…Similar to other genera of Zingiberaceae, trichomes on the leaf surfaces of C. sahuynhensis were unicellular. Liang et al (2020) and Zhao et al (2022) showed that stout trichomes were only found in the genus Curcuma, Alpinia, Amomum, and Elettaria, while the genus Kaempferia, Hedychium, and Zingiber have both delicate and stout trichomes types. Additionally, delicate trichomes were only found on the epidermis of the genus Boesenbergia, Globba (Liang et al 2020;Zhao et al 2022).…”

Leaf Epidermal Comparison of Phasey Bean (Macroptilium lathyroides) and Siratro (Macroptilium atropurpureum)

“…In the botanical study, anatomical observation was widely used to increase the understanding of physiological processes and also in the taxonomical study. The anatomical approach is more convenient to distinguish species with similar morphological traits [3] or to complement the macromorphological traits that might be plesiomorphic or by-products of parallelism [4]. Some of the anatomical traits also show an evolutionary geometric relationship among characters [5], so it can be used to produce a more robust phylogenetic tree.…”

“…Leaf was one of the organs that have many variations in anatomical structures that have been considered as important taxonomical data [3,4,6], especially the epidermal tissue [7]. The epidermal tissue in the plant is the outermost tissue that plays a major role as a protective barrier to biotic and abiotic threats, while also maintaining the gas and water exchanges [8].…”

“…The derivate of epidermal can be observed in form of stomata and trichomes. These two derivates are frequently used for biosystematics studies because of their structure was influenced by the environment [3,9,10]. The prior research, trichomes can be used as a diagnostic character in Lamiaceae [11] and tribe Trifolieae of Leguminosae [12], and to provide the taxonomical feature in Caryophyllaceae [7], Piper [13], and Polygonatum [10].…”

“…The prior research, trichomes can be used as a diagnostic character in Lamiaceae [11] and tribe Trifolieae of Leguminosae [12], and to provide the taxonomical feature in Caryophyllaceae [7], Piper [13], and Polygonatum [10]. Trichomes also can be combined with stomata, crystal, and oil cell distribution as complementary data in the systematic study of the genus Zingiber [3]. In further research, those epidermal structures, particularly stomata, potentially can be used as a major tool to construct paleoclimatic because of their correlation to functional ecology [14].…”