sporophyte

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sporophyte:

see gametophytegametophyte
, phase of plant life cycles in which the gametes, i.e., egg and sperm, are produced. The gametophyte is haploid, that is, each cell contains a single complete set of chromosomes, and arises from the germination of a haploid spore.
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Sporophyte

 

an asexual generation in plants which is formed from a zygote and in which alternation of generations is part of the developmental cycle. Sporophytes develop sporangia, which bear spores by means of meiosis. The sporophyte alternates with the gametophyte—the sexual generation—which is formed from a spore and which forms gametes. The merging of gametes produces a zygote. The cells of the sporophyte and those of the zygote have a diploid set of chromosomes, whereas the cells of the gametophyte have a haploid set.

The sporophyte represents different stages in the developmental cycles of different plants. In gymnosperms and angiosperms it plays a dominant role, ensuring the development of greatly reduced gametophytes (male gametophytes are pollen grains; female ones are the primary endosperm and the embryo sac). It also dominates in ferns and laminarians, whose gametophytes (prothallia) exist separately from the sporophytes. The sporophyte occupies a subordinate position in mosses, where it is represented by a sporogonium on the gametophyte, and in a few brown algae, where it exists independently.

In plants with isomorphic cycles of development, such as some green and brown algae, independently existing sporophytes and gametophytes are marked by a morphologically similar development. In a majority of Florideae (red algae) the sporophyte seems to have two phases of development: the first, the carpospo-rophyte, develops on the gametophyte; the second lives independently and develops similarly to the gametophyte. Hetero-morphic cycles of development, with a sporophyte that produces numerous spores, are especially characteristic of all higher plants except mosses. The establishment in plants of such cycles of development is due to the emergence of algal ancestors onto dryland, where reproduction by spores was more advantageous. The transition from isospory to heterospory led to the development of seeds and to a more perfect type of reproduction in plants—seed reproduction.

A. N. SLADKOV

sporophyte

[′spȯr·ə‚fīt]
(botany)
An individual of the spore-bearing generation in plants exhibiting alternation of generation.
The spore-producing generation.
The diplophase in a plant life cycle.
References in periodicals archive ?
Mycorrhizal-like interaction between gametophytes and young sporophytes of the fern Dryopteris muenchii (Filicales) and its fungal endophyte.
Some authors stated that, in this species, fertilization occurred and normal sexual sporophytes were formed (Nayar 1960).
Each stem was examined for the presence of perichaetia, perigonia and sporophytes, the number of each was recorded and sex expression of stems determined.
Samples from each treatment were analyzed in triplicate by an atomic absorption spectrophotometer in a graphite oven (AAS 110, Varian) to assess the concentration of lead accumulated in the sporophytes.
001): in 840 nest surveys conducted during the experiment (5 nests per sporophyte, 12 sporophytes, and 14 survey days) two adult females were observed together in one nest on only 6 occasions.
The gametophyte (haploid) stage or generation is the dominant form for lower (nonvascular) plants--the sporophyte begins less evident and smaller.
Sporophyte is found in abundance with foot, seta and capsule.
This type is followed again by most cormophytic fern sporophytes, as Hypolepis or Polypodium species demonstrate (Figs.
giganteum are also based on Iberian specimens, while those of Straminergon stramineum were described from non-Iberian specimens kept at S and BM during the visits of one of the authors to these institutions, since there were no sporophytes in any of the studied Iberian specimens belonging to this species.
1] sporophytes, the haploid production efficiency for the se male gametes in heterozygous (Sese) [F.
Volatile emissions from sporophytes and gametophytes were trapped using Solid Phase Micro extraction (SPME), separated and identified using Gas Chromatography--Mass Spectrometry (GC-MS).