Figure 4
From: Embryo sac formation and early embryo development in Agave tequilana (Asparagaceae)
Mature embryo sac or megagametophyte of Agave tequilana Weber. a) Whole mature embryo sac showing the contents of both the chalazal and the micropylar poles. b) Polar nuclei at the chalazal end before karyogamy. c) Central cell nucleus after karyogamy took place. d) Egg apparatus composed by two synergid cells and the egg cell. ch = chalaza, ea = egg apparatus, m = micropyle, da = degenerating antipodal cell, ccn = central cell nucleus, ccv = central cell vacuole, pni = polar nuclei, s = synergid cells, ec = egg cell. Arrowheads = degenerating antipodal cells. Bars = 20 μm.