apomixis

views updated Jun 11 2018

apomixis Asexual reproduction in plants without fertilization or meiosis. Agamospermy occurs when a diploid embryo sac (sporophyte) develops by the somatic division of a nucellus or integument cell; no meiosis takes place so that the diploid sporophyte gives rise directly to a diploid gametophyte. Apogamy occurs (in ferns) when the converse occurs, a diploid gametophyte giving rise directly to a diploid sporophyte. Apomixis is also used to denote vegetative reproduction in which part of a plant may become detached and develop into a separate individual without any sexual reproduction.

apomixis

views updated May 14 2018

apomixis (agamospermy) A reproductive process in plants that superficially resembles normal sexual reproduction but in which there is no fusion of gametes. In apomictic flowering plants there is no fertilization by pollen, and the embryos develop simply by division of a diploid cell of the ovule. See also parthenocarpy; parthenogenesis.

apomixis

views updated Jun 08 2018

apomixis In plants, asexual reproduction that does not involve fertilization or meiosis; or vegetative propagation in which part of a plant becomes detached and develops into a separate individual. The progeny of apomixis are genetically identical to their parents.

vegetative reproduction

views updated May 23 2018

vegetative reproduction Form of asexual reproduction in higher plants. It involves an offshoot or a piece of the original plant (from leaf, stem or root) separating and giving rise to an entire new plant. It may occur naturally, as in strawberries reproducing by runners, or artificially, as in a houseplant-cutting yielding a new plant.

apomixis

views updated May 18 2018

apomixis A form of reproduction that superficially appears to be sexual but actually occurs without the fusion of a male and female gamete.

vegetative reproduction

views updated Jun 11 2018

vegetative reproduction See vegetative propagation.