Cell Pattern and Ultrasculpture of Bulb Tunics of Selected Allium Species (Amaryllidaceae) and their Diagnostic Value

Abstract

Cell pattern and ultrasculpture were examined by light and scanning electron microscopy in bulb tunics of 46 Allium species to determine the diagnostic value of micromorphological characters. The study examined the diversity of these characters, evaluated their usefulness at different taxonomic levels (species, section, subgenus), and considered the results in relation to the recent intrageneric classification of the genus. Detailed characteristics are provided for the investigated species, and taxa showing the presence of calcium oxalate crystals in bulb tunic cells are indicated. The results suggest that several bulb tunic characters are of taxonomic significance in Allium as their variation between specimens of the same species was negligible; they can be useful elements of species descriptions and determination keys. Allium subgenus Allium shows considerable variation of bulb tunic ultrasculpture and hexagonal or elongated cell patterns. Differences in ultrasculpture are sufficient to distinguish species within the Amerallium subgenus. Three subgenera (Anguinum, Butomissa, Reticulatobulbosa) are characterized by fibrous tunics with reticulate ultrasculpture. Rectangular to elliptic cells with thick walls, giving the bulb tunic an almost perforated structure, are characteristic for Allium subgenus Cepa. No specific pattern was found for Allium subgenus Melanocrommyum and Polyprason. The only representative of subgenus Microscordum (Allium monanthum) showed distinct herringbone ultrasculpture. The bulbs of Allium subgenus Rhizirideum representatives can be distinguished by their linear ultrasculpture following the long axis of the elongated cells. Allium bulb tunic ultrasculpture and cell pattern show some degree of variability. These characters are of potential use in taxonomic delimitation, species determination and further study of the relationships between species, particularly in members of subgenus Amerallium.K Ke ey y w wo or rd ds s: : Allium, bulb tunic, calcium oxalate crystals, micromorphology, SEM, taxonomy, ultrasculpture.

Scape anatomy and its systematic importance in the Allium stipitatum species complex (Amaryllidaceae)

“…stipitatum which show polymorphisms in epidermal cell margins. The epidermal layer was composed of compact rectangular‐hexagonal cells with sunken stomata (equal to xerophytic as defined by Miryeganeh and Movafeghi 2009, Mashayekhi and Columbus ). Simple epidermal trichomes were seen only in the lower third of the scape in A. stipitatum .…”

“…Previous anatomical investigations revealed that features of vascular bundles (including shape, number, distribution and arrangement) and size of parenchymatous tissues is useful and characteristic for separation and delimitation of many species of Allium (Jacobsen 1979, Tanker and Kurucu 1981, Özdemir et al , 2011, Hosseinzadeh et al 2009, Miryeganeh and Movafeghi 2009, Mashayekhi and Columbus ), but until now few anatomical studies have been performed for members of the A . stipitatum complex (Fritsch 1993).…”

“…Most previous anatomical studies have showed that the presence, density and distribution of laticifers in the mesophyll of the leaf and scape provide significant tools for grouping and identifying species of Allium (Tanker and Kurucu 1981, Gregory , Miryeganeh and Movafeghi 2009, Mashayekhi and Columbus ). In addition, bulb anatomical studies have distinguished two subgenera, i.e.…”

“…The terminology for scape anatomical elements follow Mann (1952), Metcalfe (), Saghir and Mann (), Huang and Sterling (), Jacobsen (1979), Tanker and Kurucu (1981), Miceli et al (1984), Gregory (), Uysal (), Evert (), Hosseinzadeh et al (2009), Miryeganeh and Movafeghi (2009), Özdemir et al (, 2011), Yousaf et al (), Draghia et al (2013) and Mashayekhi and Columbus (). A total of 23 anatomical characters, including four binary coded qualitative traits were scored: shape of cross‐section (Sc), epidermis posture (Ep), presence of trichome (Tm), presence of fibers on outermost bundles (Fo), and 12 quantitative characters, i.e.…”

“…The most recent taxonomic treatment (Fritsch and Abbasi 2013) Previous morphological and anatomical studies have provided characters useful for separation and delimitation of subgenera, sections and species in Allium. Characters of high taxonomic importance are provided by leaf anatomy (Saghir and Mann 1969, Tanker and Kurucu 1981, Miceli et al 1984, Fritsch 1988, Uysal 1999, Yousaf et al 2008, Özdemir et al 2008, Draghia et al 2013, Mashayekhi and Columbus 2014, Li et al 2010, root anatomy (Uysal 1999, Özdemir et al 2008, Draghia et al 2013), rhizome and bulb anatomy (Jaccard and Frey 1927, Mann 1952, Huang and Sterling 1970, Gregory 1996, Prychid and Rudall 1999, Shrestha 2007, Rola 2014, Khorasani et al 2018, seed morphology (Neshati and Fritsch 2009, Bednorz et al 2011, Celep et al 2012, Lin and Tan 2017, ovary surface micromorphology (Gurushidze et al 2008, Choi et al 2011 and scape anatomy (Jacobsen 1979, Fritsch 1992, 1993, Uysal 1999, Özdemir et al 2008, Hosseinzadeh et al 2009, Miryeganeh and Movafeghi 2009. Previous investigations on the scape anatomy of Allium revealed that the shape and diameter of cross-sections, epidermis posture, thickness of cuticle ...…”