Ovular Development and Morphology of the Outer Integument of Magnolia grandiflora (Magnoliaceae)

The outer integument and funicular outgrowth complex in the ovule of Magnolia grandiflora (Magnoliaceae)

“…2A, B). As the ovule primordium elongates and slightly curves, the outer integument is initiated as a semiannular rim on the convex and lateral sides of the primordium, as described by Umeda et al (1994) (Fig. 2C).…”

“…Consequently the outer integument connects the funicular outgrowth on the inner side (Fig. 6A) where the cell files of the two lie at nearly right angles giving rise to a boundary (Umeda et al 1994; for a similar cell alignment pattern in Liriodendron tulipifera, see Matsui et al 1993). The outer integument grows longitudinally to the nucellus and transversely to the funiculus on the lateral sides and consequently overgrows the funicular outgrowth (Fig.…”

“…Data from Umeda et al (1994). EN Endostome, EX exostome, FO funicular outgrowth, II inner integument, OI outer integument.…”

“…Cabombaceae, Austrobaileyaceae, Trimeniaceae, Schisandraceae, many basal monocots, Winteraceae, Aristolochiaceae, Lactoridaceae, Degeneriaceae, Annonaceae, Idiospermaceae, most of Monimiaceae, Lauraceae, and Hernandiaceae), the outer integument is lacking on the funiculus (Yamada et al 2001a(Yamada et al , 2001b, in other words, semiannular Endress 1997, 1998;Igersheim et al 2001). Recent developmental studies have shown that the outer integument is semiannular at initiation and subsequently becomes hood-shaped in Cabombaceae (Nymphaeales); Austrobaileyaceae, Trimeniaceae (ITA); Annonaceae, Degeneriaceae, Eupomatiaceae (Magnoliales); and Winteraceae (Winterales) (Matsui et al 1993;Umeda et al 1994;Imaichi et al 1995;Yamada et al 2001a;T. Yamada, unpublished data).…”

“…The current interpretation is that the outer integument is a single, asymmetrical cupular integument (Johri et al 1992), and Igersheim and Endress (1997) regarded the outgrowth as a retarded part of the outer integument. In their developmental study of Magnolia grandiflora L., Umeda et al (1994) described the outer integument as forming a semiannular rim interrupted at the funiculus, the funicular outgrowth (called obturator) then appears in the gap of the outer integument and eventually, along with the hood-shaped outer integument, composes an envelope complex. However, the spatial relationship of the outer integument and the outgrowth in the distal micropylar region of an ovule has not been clearly documented (de Boer and Bouman 1972).…”