apospory


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Related to apospory: apogamy

apospory

a situation occurring in some plants where MEIOSIS is omitted and an ordinary diploid SPOROPHYTE cell gives rise to the spore which produces a diploid GAMETOPHYTE.
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References in periodicals archive ?
Sulklyan, "In vitro studies on apogamy, apospory and controlled differentiation of rhizome segments of the fern, Ampelopteris prolifera (Retz.) Copel," Botanical Journal of the Linnean Society, vol.
Soon after, Pringsheim (1876a) reported the experimental induction of leafy outgrowths from a moss seta without the intervening production of spores (apospory = without spores).
Apogamy and apospory demonstrated that gametophytes could transform into sporophytes, and vice versa, without the intervention of specific cells (eggs or spores).
One restriction fragment length polymorphism (RFLP) (UGT197) and one random amplified polymorphic DNA (RAPD) (OPC4) were syntenic with apospory in interspecific Pennisetum hybrids (Ozias-Akins et al., 1993).
Analyses of isozyme, protein, and RAPD markers did not identify associations with apospory in buffelgrass (Gustine et al., 1996).
Apospory is the formation of a gametophyte by the sporophyte, without the function of actual melospores.
This is particularly true, as discussed, of such often hailed points (allegedly supporting the homologous theory) as apogamy/ apospory and the presence of limited chlorophyll in allegedly reduced hepatophyte sporophytes (such as those of Ricciocarpus).
Several clones of maize chromosome 5 (including UMC72 and UMC147) and rice chromosome 2 (including RZ273), have been found to belong to the linkage group that includes the factor(s) for apospory in Brachiaria hybrids (Pessino et al., 1997, 1998).
Regarding the location of markers that have been reported as linked to apomixis in related species, Paspalum Linkage Group 4 and 5, which included clones linked to apospory in Brachiaria (Pessino et al., 1998), appear to be regions worthy of further investigation.
squamulatum, (ii) compare anomalies of callose deposition and other cytological features of apospory and diplospory with those previously reported for bispory and tetraspory, and (iii) discuss the findings with regard to the evolution of apomixis and polyspory and the eventual transfer of apomixis to major crop species.
Additional RAPD markers are needed to prepare an initial map of loci linked to the apospory locus in buffelgrass.
Reproductive modifications like apomixis, which involves the parthenogenetic development of apomeiotic eggs of unreduced embryo sacs that arise either from a somatic cell of the nucellus (apospory) or from a megaspore mother cell (MMC) with modified (meiotic diplospory) or absent meiosis (mitotic diplospory) (Nogler, 1984), have the potential of preserving heterosis over generations (Jongedijk, 1991).