Skip to main content
Fig. 4 | Botanical Studies

Fig. 4

From: Embryology of Anoectochilus roxburghii: seed and embryo development

Fig. 4

Light micrographs of embryo development of A. roxburghii at the early stages. a Light micrograph of a mature embryo sac before fertilization at 5 DAP. The egg cell (E) has an elongated shape with a prominent vacuole toward the micropylar end. Antipodal cells (arrowheads), inner seed coat (IS), outer seed coat (OS), polar nucleus (arrow), synergid (S). Scale bar = 30 µm. b Light micrograph of the zygote (Z) after fertilization at 10 DAP. At the micropylar end, one synergid has degenerated (DS), and the other synergid is still persistent (PS). The primary endosperm nucleus (arrow) could be observed within the endosperm cavity, but the endosperm eventually fails to develop. Antipodal cells (arrowheads), inner seed coat (IS), outer seed coat (OS). Scale bar = 30 µm. c An elongated zygote (double arrowhead) with a prominent vacuole (V) toward the micropylar end. No additional division of the endosperm nucleus (arrow) is observed. Inner seed coat (IS), outer seed coat (OS). Scale bar = 30 µm. d The first cell division of the zygote produces a smaller terminal cell (T) and a larger basal cell (B). Inner seed coat (IS), outer seed coat (OS). Scale bar = 30 µm. e Light micrograph showing a three-celled embryo (arrowheads), and the endosperm nucleus (arrows) has become condensed. Inner seed coat (IS), outer seed coat (OS). Scale bar = 30 µm. f The alignment of metaphase chromosomes (arrow) indicates a transverse division occurring in the basal cell of a three-celled embryo. Inner seed coat (IS), outer seed coat (OS). Scale bar = 30 µm. g A four-celled embryo resulting from the transverse division of the basal cell. The cell towards the micropylar end has become larger with a prominent nucleus and numerous small vacuoles (arrows). The cell accumulates numerous small vacuoles in preparation for the further cell elongation. Inner seed coat (IS), outer seed coat (OS). Scale bar = 30 µm. h Light micrograph showing a filamentous-shaped embryo. The suspensor cell (S) with a prominent vacuole has enlarged and elongated toward the micropylar end. A few tiny starch granules (arrowheads) are present in the suspensor cell. Inner seed coat (IS), outer seed coat (OS). Scale bar = 30 µm. i The suspensor cell (S) elongates rapidly with numerous starch granules (arrowheads) and has protruded into the cavity enclosed by the outer seed coat (OS). At this stage, the inner seed coat (IS) is degenerating (arrow). Scale bar = 30 µm

Back to article page