Seed coat ultrastructure of hard-seeded and soft-seeded varieties of Vicia sativa

Abstract

The mature seed coat structure in hard-seeded and soft-seeded varieties of Vicia sativa L. was examined by scanning and transmission electron microscopy to investigate differentiation in cytological and morphological features between these varieties. The outer layer of the seed coats was composed of macrosclereid (Malpighian) cells in the hard-seeded and soft-seeded varieties of Vicia sativa. The walls of the macrosclereid cells were thickened, and the cell vacuoles were filled with tannin. The cytoplasm of the macrosclereids contained small- and large-sized vacuoles and ribosomes, mitochondria, and endoplasmic reticulum. Under this layer there was a hypodermal layer composed of osteosclereids separated by large intercellular spaces. The bottom layer consisted of parenchyma cells. Thin-walled parenchyma cells were filled with amyloplasts that contained large starch grains, protein bodies, and a few organelles. Seed size and colour are important characteristics for distinguishing between hard-seeded and soft-seeded varieties. The hard seeds of Vicia sativa are smaller than the soft seeds. © TÜBİTAK.