Megasporogenesis and development of female gametophyte in Manglietia decidua (Magnoliaceae).

摘要

Manglietia decidua (Magnoliaceae) is the only deciduous species known in the genus. The ovules are anatropous, bitegmic and crassinucellar. The archesporium is one-celled and of hypodermal origin. The chalazal megaspore is functional and develops into the Allium type of female gametophyte. There is apparently a delay in development of the embryo while the endosperm is developing. As a cell wall partitioned the two nuclei into the first two endosperm cells, endosperm development was ab initio cellular. In the seed the outer integument became differentiated into an outer fleshy layer and an inner stony one, the inner integument persisting only at the micropylar region and forming a plugging tissue..