Female Short Shoot and Ovule Development in Ginkgo biloba L. with Emphasis on Structures Associated with Wind Pollination

Figure 4

Formation of female gametophyte in G. biloba. (a) Megasporocyte differentiated from inner nucellar tissue in late March. (b) Dyad. (c) Tetrad. (d) Functional megaspore. ((e)–(g)) Approaching pollination stage, pollen chamber formed at apex of nucellus, and free nuclear stage of female gametocyte occurred. ce, chalazal end; d, dyad; fm, functional megaspore; fn, free nucleus; me, micropylar end; mp, megasporocyte; nu, nucellus; pc, pollen chamber; st, spongy tissue; te, tetrad. Bars: ((a)–(d), (g)) = 50 𝜇m; ((e)-(f)) = 100 𝜇m.