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单词 apomixis
释义

Definition of apomixis in English:

apomixis

noun ˌapəˈmɪksɪsˌapəˈmiksis
mass nounBotany
  • Asexual reproduction in plants, in particular agamospermy.

    〔植〕无配子生殖,无融合生殖。常与AMPHIMIXIS 相对

    Often contrasted with amphimixis
    Example sentencesExamples
    • In apomixis, an embryo is created from a diploid cell in the ovule.
    • Most published work on poaceae is devoted to plant breeding issues, since apomixis - which allows hybrids to breed true - is as valuable a trait in plant breeding as in population biology.
    • The asexuality may be of any kind including apomixis (reproduction by unreduced egg cells).
    • Another example is the major impact that understanding apomixis would have on plant breeding.
    • Therefore it can be assumed that the seeds analyzed in this study were the result of neither selfing nor apomixis.
    • Polyembryonic seeds can arise through several developmental pathways and in some cases may involve apomixis stimulated by fertilization of nearby ovules.
    • During in vivo development, maternal apomixis refers to the asexual formation of a seed from the maternal tissues of the ovule, avoiding the processes of meiosis and fertilization.
    • A second explanation for the formation of seed in bagged hermaphroditic flowers can be apomixis, the formation of seed without pollination.
    • Genetic and molecular mapping studies based on the analysis of offspring from apomictic by sexual crosses have been carried out on multiple species reproducing by gametophytic apomixis.
    • Only one plant in the apomixis treatment developed two ovules.
    • It is noteworthy that according to the studies of Illg, M. brasiliensis may be apomictic, although pollinator-dependent; i.e. apomixis is triggered by pollen-tube development.
    • Pollen quality may be correlated with male fertility and apomixis.
    • No experiments were conducted to test whether or not the high fruit set observed in this species was due to apomixis.
    • Some angiosperms reproduce by apomixis, a natural way of cloning through seeds.
    • To eliminate the possibility of apomixes an additional treatment was added in 2000: flowers on 10 female plants were bagged.
    • The particular form of apomixis involves the development of a 2n embryo sac followed by fertilization of the central nuclei to form the endosperm (pseudogamy).
    • Plants also show great ranges in self-fertility from obligate outcrossing to complete selfing to apomixis (uniparental).
    • The values given in Table 3 are only indicative of the success of the crosses and should not be considered as definitive, since selfing, and probably also apomixis, took place in some of the cases.
    • Five individuals were assigned to a fifth treatment to investigate the possibility of apomixis.
    • There are two types of thelytokous reproduction: apomixis - clonal reproduction, which can be diploid or polyploid - and automixis, a meiosis that takes place after which diploidy is restored.

Derivatives

  • apomictic

  • adjective
    Botany
    • Parthenogenetic weevils are apomictic.
      Example sentencesExamples
      • A major scientific goal in the last decade has been to isolate genes specifically expressed in apomictic genotypes.
      • Maternal apomictic embryos develop from a somatic cell within the ovule or from an unreduced embryo sac derived from the megaspore mother cell (diplospory).
      • They are all native to the subtropical and temperate regions of South America, and sexual diploids and apomictic polyploids are known for almost all of them.
      • Such plants are very rare in other apomictic plant species.
      • However, some tetraploid lines are facultatively apomictic and an individual plant may set seed both apomictically and sexually.
      • The gene(s) controlling apomictic reproduction in Tripsacum have been assigned to the long arm of chromosome 16.
      • However, this seems unlikely since, as far as we know, no apomictic taxa of Primulaceae have been detected.
      • First, like many other members of the rose family (including apples), it is apomictic.
      • In a highly inbred or apomictic group, every individual would be a species according to the biological species concept.
      • Expression of four oleopollenin genes in eight individuals of the predominantly apomictic species Boechera holboellii.
      • The resulting hybrids often are apomictic and locally distributed.
      • The results show that early fertilization leads to the formation of apomictic embryos while fertilization at anthesis favours the formation of sexually derived embryos.
      • This primary function of pollen is a constraint that suffices to explain why apomictic grasses make pollen.
      • Furthermore, apomictic reproduction has been found in most polyploid Corollinae species, which, if transferred to cultivated beet, has the potential to improve the fixation of desired genotypes in breeding programmes.

Origin

Early 20th century: from apo- + Greek mixis 'mingling'.

Definition of apomixis in US English:

apomixis

nounˌapəˈmiksis
Botany
  • Asexual reproduction in plants, in particular agamospermy.

    〔植〕无配子生殖,无融合生殖。常与AMPHIMIXIS 相对

    Often contrasted with amphimixis
    Example sentencesExamples
    • A second explanation for the formation of seed in bagged hermaphroditic flowers can be apomixis, the formation of seed without pollination.
    • The asexuality may be of any kind including apomixis (reproduction by unreduced egg cells).
    • Therefore it can be assumed that the seeds analyzed in this study were the result of neither selfing nor apomixis.
    • Most published work on poaceae is devoted to plant breeding issues, since apomixis - which allows hybrids to breed true - is as valuable a trait in plant breeding as in population biology.
    • Five individuals were assigned to a fifth treatment to investigate the possibility of apomixis.
    • Plants also show great ranges in self-fertility from obligate outcrossing to complete selfing to apomixis (uniparental).
    • Genetic and molecular mapping studies based on the analysis of offspring from apomictic by sexual crosses have been carried out on multiple species reproducing by gametophytic apomixis.
    • To eliminate the possibility of apomixes an additional treatment was added in 2000: flowers on 10 female plants were bagged.
    • The values given in Table 3 are only indicative of the success of the crosses and should not be considered as definitive, since selfing, and probably also apomixis, took place in some of the cases.
    • During in vivo development, maternal apomixis refers to the asexual formation of a seed from the maternal tissues of the ovule, avoiding the processes of meiosis and fertilization.
    • Pollen quality may be correlated with male fertility and apomixis.
    • Some angiosperms reproduce by apomixis, a natural way of cloning through seeds.
    • Polyembryonic seeds can arise through several developmental pathways and in some cases may involve apomixis stimulated by fertilization of nearby ovules.
    • The particular form of apomixis involves the development of a 2n embryo sac followed by fertilization of the central nuclei to form the endosperm (pseudogamy).
    • No experiments were conducted to test whether or not the high fruit set observed in this species was due to apomixis.
    • It is noteworthy that according to the studies of Illg, M. brasiliensis may be apomictic, although pollinator-dependent; i.e. apomixis is triggered by pollen-tube development.
    • Only one plant in the apomixis treatment developed two ovules.
    • There are two types of thelytokous reproduction: apomixis - clonal reproduction, which can be diploid or polyploid - and automixis, a meiosis that takes place after which diploidy is restored.
    • In apomixis, an embryo is created from a diploid cell in the ovule.
    • Another example is the major impact that understanding apomixis would have on plant breeding.

Origin

Early 20th century: from apo- + Greek mixis ‘mingling’.

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