Pollen morphology and its taxonomic significance in the genus Bomarea Mirb. (Alstroemeriaceae) - II. Subgenus Bomarea

Abstract

Pollen morphology of 52 species (out of c. 79) of the Bomarea subgenus Bomarea was examined using light microscopy and scanning electron microscopy (SEM), or using SEM alone. The studied species of Bomarea were stenopalynous, characterized by large, oblate, monosulcate monads with reticulate exine sculpture in most species. Wide variation was observed in quantitative palynological features. The studied taxa were divided into four major groups based on exine ornamentation observed under SEM: microreticulate, reticulate, coarsely rugulate, and psilate-perforate. The reticulate exine sculpture may be a plesiomorphic character state for the genus Bomarea, and the coarsely rugulate and finely rugulate-perforate or psilate-perforate exine sculptures may have evolved independently more than once. In agglomerative hierarchical clustering (AHC) analyses of the genus Bomarea using quantitative pollen data, the studied species were distributed in either two (similarity-based) or four (dissimilarity-based) major clusters. Neither the recent molecular phylogenetic analyses nor the AHC analyses of Bomarea have recovered clades/clusters that represent traditionally recognized subgeneric taxa for the genus. Therefore, the most reliable infrageneric classification of Bomarea can be achieved by combining morphological, palynological, and molecular data from more extentive sampling of all the species.

Palyno‐anatomical studies of monocot taxa and its taxonomic implications using light and scanning electron microscopy

“…Study of palyno‐anatomical features has been the fascinating and a field of scientific analysis since the most primitive microscopists. The various morphological features of pollen such as shape, symmetry, exine configuration, and apertural pattern are very conservative characters for plants taxonomic evaluation (Bera, Basumatary, & Dixit, ; Keshavarzi, Abassian, & Sheidai, ; Perveen, ; Sarwar, Hoshino, & Araki, , , ). For natural classification, the usefulness of pollen morphology is as an interpretative key and now very debated (Blackmore & Barnes, ; Ghosh & Karmakar, ).…”

Pollen morphological characters variation among species of Strobilanthes s.l. from Sumatra, Indonesia and its taxonomic implications

“…They can be used to solve the taxonomic problems of plant groups, such as identification, taxa delimitation, classification and relationship assessment (Yao and Zhang 2016;Al-Hakimi et al 2017;Tripathi et al 2017;Ruiz-Domínguez et al 2019;Chen et al 2019;de Souza et al 2019;Ragho 2020). The pollen morphological characters such as polar axis length (P), equatorial diameter (E), P/E ratio, pollen sculpture or exine ornamentation (Via do Pico and Dematteis 2013;Ferrauto and Pavone 2014;Sarwar et al 2015;Al-Hakimi et al 2018), pollen size, pollen shape, exine thickness (Akhila and Beevy 2015;Krachai and Pornpongrungrueng 2015;Noedoost et al 2021) are valuable for distinguishing and identification of many plant groups.…”