Embryology of Certain Ranales
Embryology of Certain Ranales
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DOI：
10.1086/334784
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发表时间：
1938-12
影响因子：
--
通讯作者：
T. T. Earle-T.
中科院分区：
文献类型：
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作者：
T. T. Earle-T.
1.广玉兰倒生胚珠的发育方式与Gray对三瓣木兰的描述相似。2.大花莲胚囊细长，珠孔端部为棒状膨大。它含有通常数量的八个原子核。3.大花莲的胚乳在发育早期就是细胞性的，最后形成一个巨大的结构，含油但不含淀粉。4.大花菊的胚胎最初是一团未分化的细胞，胚柄巨大。由于不规则的细胞分裂，它变成了梨形。子叶从远端长出，形成独立的结构。5.总状升麻倒生胚珠的发育没有明显的特殊性。6.总状花序的胚囊为普通类型，有8个核。从纵切面上看，它呈菱形。7.总状花序早熟禾胚乳由排列在胚囊壁上的游离核组成。这些游离核周围发生壁形成，胚乳最终充满胚囊。它含有油，但不含淀粉。8.总状花序的胚胎发育类似于大花锦鸡儿的胚胎，最初由未分化的球状细胞团组成。子叶从远端长出，形成独立的结构。在胚胎的底部有一个巨大的胚柄。9.Grandiflora和Cimicifuga racemosa的胚胎发育与木兰科、毛茅科和小檗科其他物种的胚胎发育相一致。10.林蛙的胚胎学在早期似乎符合一般类型，与许多单子叶植物的情况非常相似；在其后期，它在木兰科、小梁科和毛茅科中完全是双子叶植物。11.睡莲科和金鱼草科应归入单子叶植物的建议似乎有一定的依据。
1. The anatropous ovule of Magnolia grandiflora develops in a manner similar to that described by Gray for M. tripetala. 2. The embryo sac of M. grandiflora is long and slender, and terminates in a club-shaped expansion at the micropylar end. It contains the usual number of eight nuclei. 3. The endosperm of M. grandiflora is cellular very early in its development and finally comes to be a massive structure, containing oil but no starch. 4. The embryo of M. grandiflora at first is a mass of undifferentiated cells with a massive suspensor. It becomes pear-shaped by irregular cell divisions. The cotyledons arise from the distal end as independent structures. 5. The development of the anatropous ovule of Cimicifuga racemosa shows no marked peculiarity. 6. The embryo sac of C. racemosa is of the usual type, having eight nuclei. It is rhombic in shape as seen in longitudinal section. 7. The endosperm of C. racemosa in its early stages consists of free nuclei lining the wall of the embryo sac. Wall formation occurs about these free nuclei and the endosperm finally fills the embryo sac. It contains oil but no starch. 8. The embryo of C. racemosa is similar to that of M. grandiflora in its development, consisting at first of a globular mass of undifferentiated cells. The cotyledons arise from the distal end as independent structures. There is a massive suspensor at the base of the embryo. 9. Development of the embryos of M. grandiflora and Cimicifuga racemosa corresponds to what has been found in other species of the Magnoliaceae, Ranunculaceae, and also of the Berberidaceae. 10. The embryology of the Ranales as a whole seems to conform to a general type in the early stages, closely resembling the condition found in many monocotyledons; in its later stages it is thoroughly dicotyledonous in the Magnoliaceae, Berberidaceae, and Ranunculaceae. 11. There seems to be some basis for the suggestion that the Nymphaeaceae and Ceratophyllaceae be placed in the Monocotyledonae.