apospory

von Aderkas, "Enhancement of apospory in liquid culture of Matteuccia struthioptens," Annals of Botany, vol.

Apospory in leaf culture of staghorn fern (Platycerium bifurcatum).

Since the latter were clearly homologous to each other, this meant that the moss seta (asexual generation) was homologous to the moss stem (sexual generation), as confirmed by observations of the vegetative sprouting of the seta (apospory).

Forty-nine plants (64.4%) formed some aposporous embryo sacs in addition to the normal meiotic sac, and the remaining 27 plants were free of apospory. Plant Q4205 was selected from among these 27 sexual plants.

as composed solely of two mechanisms: apospory and diplospory.

Two types of apomixis, apospory and diplospory, occur in grasses.

Apogamy ("without gametes") and apospory ("without spores") are, to an extent, misnomers, because in some instances gametes and spores are still produced in the life cycle when these phenomena occur; the chromosome complement of the apogamously tbrmed sporophyte and aposporously produced gametophyte is, however, sometimes other than the usual for these generations (for example, both gametophyte and sporophyte in the life cycle may be found to be diploid).

The grass reproduces primarily by apomixis with the mechanism being apospory followed by pseudogamy (Fisher et al., 1954; Snyder et al., 1955).

Apomixis (i.e., asexual reproduction by seeds) is a common trait in the genus, being apospory (in which a non reduced megagametophyte originates from a somatic cell, usually a nucellar cell) the most frequent type, and diplospory (in which a non reduced megaspore originates from the reproductive cell itself, with the later failing to successfully complete meiosis) only of occasional occurrence (Quarin, 1992).

The grass reproduces primarily by apomixis, with the mechanism being apospory followed by pseudogamy (Fisher et al., 1954; Snyder et al., 1955).

Gametophytic apomixis (asexual reproduction through seed) involves the formation of unreduced embryo sacs from the MMC (diplospory) or from nucellar cells (apospory).

Crosses of sexual with aposporous genotypes of buffelgrass yielded segregation ratios compatible with an inheritance model that postulates expression of apospory requires the dominant allele (A) of a single autotetrasomically inherited locus, assuming random assortment of chromatids (Sherwood et al., 1994).