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

Figure 3

Development of tissues for pollen capture and transport in G. biloba. ((a)-(b)) After nucellus differentiation, integument continued to grow upward, surrounding nucellus. ((c)-(d)) Tip of integument gradually fused toward the center on top of nucellus. ((e)–(h)) Tip of integument continued growing upwards. (i) Formation of micropyle. (j) Micropylar canal. ((k), (k-1)) Cells of micropylar canal with smooth surfaces. (l) Column-shaped nucellus and developing micropylar canal. ((m)-(n)) Tip of nucellus became slightly acute. ((o)-(p)) Emergence of pollen chamber. ((q)-(r)) Ovules during pollination period with well-developed micropyle, micropylar canal, and pollen chamber. i, integument; mi, micropyle; mc, micropylar canal; nu, nucellus; oc, ovular collar; pc, pollen chamber. Bars: ((a)–(j), (l)–(p)) = 100 𝜇m; (k) = 50 𝜇m; ((q)-(r)) = 500 𝜇m.