Seed Morphology of Allium L. Endemic Species from Section Schoenoprasum (Amaryllidaceae) in Eastern Kazakhstan.

Abstract

The genus Allium is highly diverse and ecologically significant in Eastern Kazakhstan, with several rare and endemic species belonging to the section Schoenoprasum. This study provides a comparative analysis of the seed morphology of four species from this section: A. ledebourianum, A. ivasczenkoae, A. schoenoprasum, and A. ubinicum. Seeds were collected from their natural habitats and analyzed through morphometric measurements, surface structure assessments, and environmental correlation. Distinct differences in seed length, width, thickness, and weight were identified, with A. ubinicum displaying the most pronounced divergence in size and mass. Qualitative traits, including surface texture, micropyle visibility, and chalaza structure, were also recorded. Principal component and cluster analyses revealed clear separation between the species, notably distinguishing A. ubinicum from A. schoenoprasum, challenging their previously assumed synonymy. Environmental variables such as light, moisture, and soil chemistry showed significant correlations with seed dimensions, suggesting that environmental conditions contribute to morphological differentiation. Although the micromorphological features observed under scanning electron microscopy were generally similar, the macromorphological traits proved to be taxonomically informative. The larger and heavier seeds of A. ubinicum suggest regional divergence or adaptive evolution, reinforcing its classification as a separate taxon. These findings contribute to the refinement of the species delimitation process within Schoenoprasum and underscore the role of seed traits in both taxonomic research and conservation strategies in floristically rich but understudied regions like Eastern Kazakhstan.