Taxonomic Importance of Seed Morphology in Allium (Amaryllidaceae)

Allium is one of the largest monocotyledonous genera. Southwest to Central Asia is the major center of diversity for the genus. In the present study, seeds of 62 Allium taxa from Turkey classified in subg. Allium (sect. Allium, sect. Brevispatha, sect. Codonoprasum and sect. Multicaule), subg. Amerallium (sect. Molium), subg. Melanocommyum (sect. Acanthoprason and sect. Melanocrommyum), and subg. Polyprason (sect. Falcatifolio and sect. Scorodon) were examined using light and scanning electron microscopy to evaluate the taxonomic relevance of macro- and micro-morphological seed characters. As a result of the study, species-specific and section-specific characters have been determined. Seeds exhibit variation in size and shape of testa cells, shape and sculpturing of periclinal walls, as well as position, shape and undulation type of anticlinal walls. Seeds ranged from 1.57-5.10 mm in length and 0.81-4.05 mm in width. Six different ovate seed shapes were recognized with a length to width ratio ranging from 1.30 +/- 0.09-2.64 +/- 0.41. Shape of testa cells, shape, and sculpturing of periclinal walls, and position, shape, and undulation type of anticlinal walls were found to be important diagnostic characters. Seed coat patterns appear to mark different evolutionary levels inside of many taxonomic groups and variation of the testa characters is sufficient to distinguish taxa at sectional level. However, seed coat patterns do not directly indicate basal or advance evolutionary levels.