| 词汇 | endosperm |
| 释义 | endosperm noun[ U ] biology specializeduk /ˈen.dəʊ.spɜːm/ us /ˈen.doʊ.spɝːm/ the substance inside a plant seed that surrounds and provides food for the embryo as it develops胚乳（植物种子内包裹胚芽并在其发育过程中为其提供养分的物质） Plant reproduction anther asexual reproduction asexuality asexually barrenness breeder chasmogamous germinate palynology pistillate placentation pollinate pollination self-fertilize self-incompatible self-pollination sexlessly siltation stamen wind pollination You can also find related words, phrases, and synonyms in the topics: Fruits & seeds & their parts As a rule the embryo is very small and surrounded by abundant endosperm. In cases where the embryo has stored reserve food within itself and thus provided for self-nutrition, such endosperm as remains in the seed may take on other functions, for instance, that of water-absorption. The formation of endosperm starts, as has been stated, from the endosperm nucleus. The function of the endosperm is primarily that of nourishing the embryo, and its basal position in the embryo-sac places it favourably for the absorption of food material entering the ovule. This apparently profitable machine permitted the miller to efficiently separate wheat flour into three components: bran, germ and endosperm. Examples of endospermendosperm The endosperm has a very thick peripheral cell wall (cw). The cytokinin or ethylene requirements for overcoming thermoinhibition of lettuce germination can also be eliminated or diminished by removing or weakening the endosperm. Or does the radicle elongate to the extent of pushing against the endosperm before endosperm degradation begins? An alternative explanation is that endosperm softening requires more than mannan degradation. This suggests that these storage polymers are responsible for the shape of the typical endosperm spectrum. As described above, the endosperm of the mature grain is packed with storage polymers rich in carbohydrate, protein and lipid. Cellular membrane integrity was studied in developing endosperm during differentiation and maturation. At stage 8, the endosperm changed from a liquid to viscous consistency and occupied only 50% of the seed volume. After 28 d, embryos had grown to 0.6 mm2 and occupied nearly 60% of the mucilaginous endosperm within which the embryo develops. A very thin endosperm (es) surrounds the embryo, leaving spaces of free water (w) in between. The size of the endosperm that contains essential protein, starch and other nutrients is an important criterion for crop breeding programmes. As the most important source of staple grains, the endosperm is measured for a phenotypic trait of interest. Statistical methods for dissecting triploid endosperm traits using molecular markers : an autogamous model. Rather, a stimulus released from the cotyledon is more likely to induce the major cell wall degrading enzyme, endo- mannanase, within the endosperm itself. Naked embryos were sensitive to imbibitional stress, whereas embryos with an intact, thick-walled endosperm were not. These examples are from corpora and from sources on the web. Any opinions in the examples do not represent the opinion of the Cambridge Dictionary editors or of Cambridge University Press or its licensors. |
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