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The nutritive protein material within the embryo sac of seed plants.
Storage tissue in the seeds of gymnosperms.



in the seed of gymnosperms and most flowering plants, a tissue in which the nutrient substances necessary for the development of the embryo are deposited. In gymnosperms the endosperm is formed in the ovule during germination of the megaspore; it consequently becomes the female prothallus (gametophyte), with a haploid set of chromosomes. The archegonia in gynosperms develop from certain cells of the endosperm. In angiosperms the endosperm is formed after fertilization as a result of the merging of the spermatozoid with the secondary (diploid) nucleus of the embryo sac. In this case the cells of the endosperm are triploid. By uniting sets of chromosomes from both parent plants the endosperm becomes a physiologically active, viable nutrient tissue. It not only feeds the embryo but fosters embryonic growth and differentiation.

A distinction may be made between the nuclear, cellular, and helobial types of endosperm. In the first type the cell walls do not form immediately after formation of the nuclei. In cellular endosperms the cell walls form immediately after each division of the nuclei. Helobial endosperm is intermediate between the other two types. Endosperm is not equally developed in the mature seeds of flowering plants of different families. Thus, it is large in Gramineae, Solanaceae, and Umbelliferae, but in many other families, for example, Leguminosae, Compositae, and Rosaceae, the endosperm is poorly developed, and reserve nutrient matter is deposited in the embryo itself, mainly in the cotyledons. In many Orchidaceae the endosperm is not formed.


Khudiak, M. I. Endosperm pokrytosemennykh rastenii. Kiev, 1963.
Poddubnaia-Arnol’di, V. A. Tsitoembriologiia pokrytosemennykh rastenii. Moscow, 1976.
References in periodicals archive ?
These processes occur in specific organelles that may be present in the embryo and/or reserve tissues, such as the endosperm.
Cytokinins are present in developing seeds and accumulate predominantly in the liquid endosperm (Emery et al.
The concentrations of all protein fractions, except for the glutelins, were higher in endosperms obtained from the growth chamber study than from endosperms from field-grown plants (Fig.
The significance of genic balance to endosperm development in interspecific crosses.
It is important to know that few studies have determined vitreousness by manual dissection of the vitreous and farinaceous endosperm in corn hybrids, a methodology which enables the confident assignment of the real vitreousness pattern of a genotype (Davide, Ramalho, Figueiredo, & Souza, 2011; Osorio-Diaz et al.
Temperature at filling stage also exerted a remarkable impact on the percentage distribution of different chain-length fractions of amylopectin, thereby affecting the fine structure of starch granules in rice endosperms (Yamakawa et al.
On three mutant loci for endosperm properties, ge (giant embryo), du-4 (dull endosperm-4) and flo-1 (floury endosperm-l).
We also discuss the relationships between changes in polyamine concentrations, endosperm cell number, and DNA content for normal and aborting maize kernels.
1995b), while post-pollination water deficit did not substantially affect sugar concentrations in developing endosperms (Ober et al.
The mitotic DNA content for endosperms of kernels exposed to 4-d HTT imposed at 4 or 6 DAP also declined over the period sampled, but remained significantly higher compared with that of the control endosperm at 14, 16, and 18 DAP (Fig.
Endosperms were collected (250 postpollination accumulated HU) during the period when kernel growth rate was also being measured and, hence, entailed a stage of temperature-induced growth impairment.