Seed Morphology of Allium L. (Amaryllidaceae) from Central Asian Countries and Its Taxonomic Implications

Abstract

We studied seed macro- and micro-morphological characteristics of 48 Allium species (51 accessions) belonging to 24 sections and 7 subgenera. Our taxonomic sampling focused on the central Asian regions of Uzbekistan, Kyrgyzstan, and Mongolia. The seed length ranged between 1.74 ± 0.16–4.47 ± 0.43 mm and width ranged between 1.06 ± 0.08–3.44 ± 0.23 mm, showing various shapes. The irregular and elongated polygonal testa cells occurred in all investigated species. Seed testa sculptures showed high variation in their anticlinal walls associated with different shapes: straight to with U-, S- or Omega-type undulations among the species. The moderately flat to convex periclinal walls with various sized verrucae or granules were found in all investigated taxa. Based on our research, we conclude that seed characteristics such as size, shape, and the seed testa features show their significant variability, revealing key characteristics to support taxonomic relationships and major clades recovered in the molecular phylogeny of the genus Allium. Especially, the anticlinal wall characteristics were highly variable and decisive at the both section and species levels. In addition, widely varied shapes and sizes of the seeds were remarkably effective to distinguish Allium species.

Seed testa sculpture of species of Allium L. (Amaryllidaceae) and its taxonomic implications

“…Recently, seed testa sculpture of Allium have been quite well studied from different countries based on the herbarium and field collection materials (Celep et al, 2012; Lin, Tan, 2017; Veiskarami et Seed testa sculpture of Allium L. (Amaryllidaceae) al., 2018; Baasanmunkh et al, 2020). In this study, we investigated seed testa sculpture of 24 species in genus Allium L. based on herbarium materials and seed collected in the living Allium collections in Institute of Plant Genetics and Crop Plant Research, Gatersleben, Germany and Botanical Garden of the Osnabrueck University, Germany (GAT and OSN accessions in the table 1, respectively).…”

“…Terminologies for the description of seed testa sculpture is according to Barthlott (1981), Celep et al (2012) and Baasanmunkh et al (2020).…”

“…Seed morphology and seed testa studies have been suggested to be taxonomically useful for species and section rank detection in the genus Allium. Seed testa sculpture of anticlinal wall with S-, U-, Omega-, and straight type undulation and one central verruca with marginal verrucae or densely granulose periclinal wall are important characters to sections and subgenera level (Baasanmunkh et al, 2020). For instance, straight anticlinal walls were dominated in subg.…”

“…The U-, Omega-and S-type undulation anticlinal walls and convex periclinal walls with several large verrucae or marginal verrucae were dominated in subg. Allium and Melanocrommyum (Celep et al, 2012;Lin, Tan, 2017;Veiskarami et al, 2018;Baasanmunkh et al, 2020). Additionally, several new taxa of Allium have been recognized based on their morphology including seed macroand micro-morphological characteristics and phylogenetic studies (Deniz et al, 2015;Duman et al, 2017).…”

“…To date, seed morphology and seed testa sculpture of 460 taxa have been studied from different countries (Baasanmunkh et al, 2020). In particular, most of species were investigated from the Turkey, Iran and Central Asian countries (Celep et al, 2012;Lin, Tan, 2017;Veiskarami et al, 2018;Baasanmunkh et al, 2020). However, seed morphological studies of many species and sections of Allium is remaining.…”