<p><strong>Comprehensive analysis of <em>Actiniopteris</em> Link and <em>Onychium</em> Kaulf. (Pteridophyta) relationships according to their phylogeography, phylogeny and spore morphology</strong></p>

Abstract

This research is the first comprehensive analysis of the intrageneric relationships of Actiniopteris and Onychium based on original data including spore morphology, phylogeny and phylogeography. Actiniopteris and Onychium are members of the large subfamily Pteridoideae of the family Pteridaceae. The Pteridaceae family is considered one of the most taxonomically confusing families due to its representatives high level of polymorphism. We used an interdisciplinary approach to study the “Onychium clade”: 13 taxa were studied using scanning electron microscopy (SEM) to characterize the morphology and morphometry of spores; 14 taxa were studied from a phylogenetic perspective, including character evolution and ancestral character state reconstructions; 15 taxa of “Onychium clade” were studied using herbarium data (B, P, PE, LE, VLA, TI, KYO, ALTB and TK) according to global botanical and geographical zones. As a result of this integrated analysis, we established a deep divergence of the taxa O. tenuifrons and O. siliculosum from the main composition of the genus Onychium and the division the genus Actiniopteris into two clades: A. radiata–A. semiflabellata and A. australis–A. dimorpha. We found that representatives of Actiniopteris and Onychium had originated in a common African-Indo-Malesian area. The “Onychium clade” center of diversity is the Indian Region, which is experiencing high levels of human impact, leading to disjunctions among the studied taxa.

Taxonomy and spore morphology of selected taxa of Cheilanthoideae and Pteridoideae (Pteridaceae) from Pakistan

“…The spore morphology Onychium cryptogrammoides subsp. cryptogrammoides and O. vermae are trilete, triangular in proximal, distal view, ellipsoidal, hemicircular in equatorial view; spore surface was granulose, tuberculate which agreed with Lee et al (1990) and Vaganov et al (2017, 2020). The spores of Pteris cretica subsp.…”

“…emodi), terminate more abruptly into a usually long apical segment; frond apex suddenly reduced to an abrupt, usually long drooping terminal segment; lamina unipinnate, oblong, lanceolate (Figure 6f); sori located on the overall both margins of lamina, spore trilete, triangular with laesura in proximal view, spheroidal, hemispherical at distal view with spinulose, tuberculate surface, equatorial view with equilateral flange at the middle, size 36-45 Â 37-48 μm, surface cristate, granulose, tuberculate at proximal view, granulose, cristate at distal view (Figure 10a-c). The spore morphology of Cheilanthoideae and Pteridoideae (Pteridaceae) species observed under SEM represents variations in size, shape, aperture and surface ornamentation, as described in many previous studies (Giacosa, Morbelli, & Giudice, 2004;Makgomol, 2006;Nayar & Devi, 1966, 1967Vaganov, Gureyeva, Shmakov, Kuznetsov, & Romanets, 2018a, 2018b et al ( ) and Vaganov et al (2017et al ( , 2020. The spores of Pteris cretica subsp.…”

“…The spore of Actiniopteris radiata were trilete, triangular, distal side hemispherical, proximal side triangular, convex, proximal equatorial side ellipsoidal with equatorial ridge, distal surface cristate, proximal surface tuberculate, size 35–45 × 45–50 μm. Nayar and Devi (1967) reported spore size 47 × 60 μm, with trilete, tetrahedral shape and verrucate and rugulose ornamentation; while Vaganov et al (2020) reported spore size 46 × 49 μm. The spores of Aleuritopteris albomarginata and A. ancepes were observed to be trilete, tetrahedral, that agreed with the earlier work of Sen and Mukhopadhay (2011) and Tryon and Lugardon (1991).…”

“…Duthie (1898); Hope (1896) documented nine taxa of Pteridaceae from northern areas, Pakistan; Stewart (1972) documented 6 genera with 22 taxa of Cheilanthoideae and Pteridoideae from Pakistan; Lee, Oh, and Lee (1990) documented the taxonomy and spore morphology of Pteridaceae from Korea; Nakaike and Malik (1992, 1993) reported 4 genera with 11 taxa of Cheilanthoideae and Pteridoideae from various localities of Azad Jammu and Kashmir, Gilgit‐Baltistan, Hazara and Malakand divisions; Morbelli, Ponce, MacLuf, and Piñeiro (2001) documented the spore morphology of Notholaena species through scanning electron microscopy from South America. Sen and Mukhopadhay (2011) documented the spore morphology of five Species of Cheilanthes through LM and SEM from India; Fraser‐Jenkins (2014) and Fraser‐Jenkins et al (2016) documented 8 genera with 26 taxa of Cheilanthoideae and Pteridoideae, with a comprehensive specimen based inventory of the pteridophytes of Pakistan; Gul, Alam, Ahmad, and Irfan (2016) reported 5 genera with 18 taxa of Cheilanthoideae and Pteridoideae from district Mansehra, Pakistan; Chao, Mustapeng, Chen, and Chiou (2017) evaluated the spore morphology of Pteris borneensis , P. decrescens and P. parviloba , Pteridaceae through SEM from Borneo Island; Masoumi, Ghasempour, and Sobhi (2017) documented the spore morphology and developmental stages of Cheilanthes persica from Kermanshah, Iran; Vaganov, Gureyeva, Kuznetsov, Shmakov, and Romanets (2017) documented the spore morphology through SEM of Onychium ippi , Pteridoideae, Pteridaceae from China; Chao and Huang (2018) documented the spore morphology through SEM of 57 species of pteridaceae; Shah, Çelik, Ahmad, et al (2019) reported 10 species from Northern Pakistan; Vaganov, Metzgar, Sinitsyna, and Shmakov (2020) documented the phylogeny, phylogeography and spore morphology of Actiniopteris and Onychium species.…”

“…spore of Actiniopteris radiata were trilete, triangular, distal side hemispherical, proximal side triangular, convex, proximal equatorial side ellipsoidal with equatorial ridge, distal surface cristate, proximal surface tuberculate, size 35-45 Â 45-50 μm Nayar and Devi (1967). reported spore size 47 Â 60 μm, with trilete, tetrahedral shape and verrucate and rugulose ornamentation; whileVaganov et al (2020) reported…”