Pollen morphology and its implication in the taxonomy of some selected taxa of the bi and tri‐ovulate Euphorbiaceae of the Hainan Island by using multiple microscopic techniques

Abstract

The family Euphorbiaceae is one of the most taxonomically complex and diverse family among the angiosperm. Therefore, this study aims to document the pollen morphology of the Euphorbiaceae taxa collected from different geographical regions of the Hainan Island South China, to strengthen the taxonomy and support the subfamilial classification. The Euphorbiaceae includes 23 species and 10 genera of the biovulate subfamily Phyllanthoideae and tri-ovulate Crotonoideae, Euphorbioideae, and Acalyphoideae were examined under light and scanning electron microscopy. The principal component analysis was performed by using six variables to show variation and relationships between the species. A significant variation was found in the pollen morphology (exine and colpus sculpturing). The croton-type pattern of the pollen was found the diagnostic trait of the Crotonoideae. The Euhphorboideae taxa were mostly homogenous however, variation was found in the muri pattern. The Acalyphoideae, have fossulate scabrate and verrucate exine sculpturing that can delimit from the rest of sub-families. The Phyllanthoideae, showed reticulate exine, tri to tetra-colporate having various colpus morphology. The maximum pollen size was found in Croton hirtus (59.49 Â 60.86 μm) and minimum in Acalypha indica (10.86 Â 73 μm). Similarly, the maximum colpus width was observed in Euphorbia pulcherrima (8.3 μm). Hence pollen traits have relevance in the taxonomy and phylogenetic of the family to define species boundaries at various taxonomic levels. This study can support and strengthen the taxonomy of subfamilies and fill the palynological gap of these taxa in Hainan Island and will contribute to future systematic studies of the Euphorbiaceae. Highlights• Some selected taxa of the four subfamilies including Crotonoideae, Euphorbioideae, Acalyphoideae, and Phyllanthoideae (Euphorbiaceae) were collected from different geographical regions of the Hainan Island.• The pollen of these taxa was observed under both light and scanning electron microscopy.

Exploration of pollen traits and their taxonomic relevance in selected taxa of the subfamily Papilionoideae from Hainan Island, China

“…The prepared aluminum stub was then put in SEM (Model Thermo Scientific, Model: verios g 4uc) installed in the analytical and testing center of Hainan University. The photomicrographs were then taken by observing various pollen morphological features (polar axis, equatorial diameter, colpus length and width and polar area diameter) by following the previously published protocol (Bahadur et al 2022a). The pollen terminology is mostly followed by that of Halbritter et al (2018) and Punt et al (2007).…”

Palynological investigation of some Euphorbia L. (Euphorbiaceae) taxa from Turkey using light and scanning electron microscopy

“…Morphologically and palynologically, Euphorbia has been well studied worldwide (Alam et al, 2021; Alyas et al, 2020, 2021; Bahadur et al, 2022; Chaudhary & El‐Ghazaly, 1994; El‐Ghazaly, 1989; El‐Ghazaly & Chaudhary, 1993; Furness, 2011; Lee & Park, 2006; Nobarinezhad et al, 2018; Noh & Park, 2008; Oh et al, 2002; Park, 1997; Perez de Paz & Roca‐Salinas, 1977; Perveen & Qaiser, 2005; Punt, 1962; Shahzad et al, 2022; Weber El Ghobari, 1985; Xia et al, 2008); however, these studies are still insufficient considering the diversity and wide distribution of the genus.…”

Shifts in Community Vegetative Organs and Their Dissimilar Trade-Off Patterns in a Tropical Coastal Secondary Forest, Hainan Island, Southern China

“…Tropical coastal secondary forests have been seriously affected not only by natural disasters (e.g., typhoons), but also by human disturbances (i.e., slash and burn) [27]. The natural forest flora of southern China has a rich diversity of various plants groups and is represented by this tropical coastal secondary forest, which has a selected parallel ecology [28][29][30][31][32]. Biodiversity conservation, monitoring of the natural environment, and controlling typhoons are thus serious issues in this region [27].…”