Spore morphology and leaf epidermal anatomy as a taxonomic source in the identification of Asplenium species from Malakand division Pakistan

Abstract

Several studies have demonstrated the usefulness of leaf epidermal, and spore morphological characters in the taxonomy of genus Asplenium. However, works on the Pakistani species of Asplenium are not existent. With the objective to verify the efficacy of leaf epidermal and spore morphological traits, the leaf epidermis and spore morphology in nine Asplenium species occurring in Malakand division was studied. The spores were studied under light microscope (LM) and scanning electron microscope (SEM), whereas for leaf epidermal anatomy, the LM was used. The spores are monolete, ellipsoidal in shape, the equatorial and polar diameter ranges between 28.3 and 50.2 × 27.6 and 45.8 μm. The exospore thickness varied from 0.5 to 3.8 μm. The perispore is 0.8-3.5 μm thick, ornamented, and morphologically variable. The spores characters specifically the perispore ornamentation are useful in distinguishing species within the genus. The irregular spore shape and unusual development of perispore wall surface characterize aborted spores in the species of Asplenium × alternifolium. The most informative quantitative characters appeared to be length and width of epidermal cells, and length and width of stomata were useful to distinguish species. The most significant qualitative characters to distinguish species were the anticlinal wall pattern. Our study has shown that considerable variations exist in the leaf epidermis of Asplenium species, at least some of which has taxonomic significance. We confirmed the prevalent taxonomic value of stomatal and epidermal cells traits. The leaf epidermal anatomy and spore morphological features showed to be a good source of information for taxonomy of the genus Asplenium.

Taxonomic importance of spore morphology of selected taxa of Asplenium (Aspleniaceae) from Pakistan

“…fontanum subsp. pseudofontanum was monolete having bilateral symmetry, distal view was spheroidal, proximal view ellipsoidal, average spores size were 31–36 × 36–42 μm; perispore surface with costate‐alate fold type; anomofenestrate fenestration; reticulate, echinate ornamentation, and with lophate pattern; that agreed with the earlier study (Morbelli & Giudice, 2005; Nayar & Devi, 1964; Shah et al, 2020); while Nayar and Devi (1964) documented spore size 26–30 × 30–34 μm; Shah et al (2020) reported spore size 40.7–55.7 × 30.3–50.4 μm. The spores of A .…”

“…trichomanes subsp. quadrivalense was monolete having bilateral symmetry; distal and proximal view was ellipsoidal, spheroidal; average spore size were 31–35 × 36–42 μm; perispore surface with arelofenestrate fenestration; costate‐alate fold type; veined ornamentation and with lophate pattern; that agreed with the earlier study of Lashin (2012); Nayar and Devi (1964); while Shah et al (2020) documented spore size 30.2–50.9 × 30.8–45.5 μm. The spores of A .…”

“…The taxonomic importance of spore micromorphology with ferns is well established; spore morphology by using scanning electron microscopy is very useful in the taxonomy of complex ferns taxa (Adeonipekun et al, 2021; Gorrer et al, 2021; Makgomol, 2006; Morajkar et al, 2021; Vaganov et al, 2017). Asplenium spores are variable in size, shape and perispore morphology, ornamentation and its surface, being consistently monolete, frequently ellipsoidal, have prominent folds with alate, costate, cristate, echinate, and reticulate perispore that is usually fenestrated in areolae between the folds (Regalado & Sanchez, 2002; Shah et al, 2020).…”

Assessment of floristic diversity in the mountain ecosystem of Marghazar Valley, Hindukush Range, Swat, Pakistan

“…Specimens (flowering plants) were identified with the help of native flora (flora of Pakistan) and other available literature Nasir 1989-1991;Nasir 1991-1993;Ali and Qaiser 1986;Qaiser 1993-2017;Qaiser 2000-2012;Ali 1978;Ali 1980;Ali et al 2001;Cronquist 1968;Nasir 1981;Stewart 1967;Stewart 1972), grasses identified with the manual of (Cope 1982;Ahmad et al 1958). Fern and their allies (Pteridophytes) was identified from (Gul et al 2017;Lellinger 2002;Nakaike and Malik 1992;Nakaike and Malik 1993;Nayar 1964;Stewart 1957), flora of China (Zhang et al 2013) and other available literature (Beddome 1866;Beddome 1873;Clarke 1973;Fraser-Jenkins 2014;Hope 1899Hope -1902Shah et al 2020Shah et al , 2021. Plant samples were also confirmed from snapshots existing on the international herbaria website.…”

Morpho‐palynological and anatomical studies in desert cacti (Opuntia dillenii and Opuntia monacantha) using light and scanning electron microscopy

“…The anthers were crushed and treated with acetic acid to release the pollen material from it. For staining glycerin jelly was used (Ahmed et al, 2019; Ashfaq et al, 2018; Shah et al, 2020; Zafar et al, 2019; Zafar et al, 2020). The prepared pollen slides were observed under light microscope and photographs were taken at 40× magnification under Nikon FX‐35 Camera equipped with photomicrograph system.…”