美國人蔘의 形態 및 發生學的硏究 = MORPHOLOGICAL AND EM BRYOLOGICAL STUDEIES ON THE AMERICAN GINSENG(PANAX QUINQUEFOLIUM L.)

다국어 초록 (Multilingual Abstract)

The present study attempts to examine the morphological and embryological phenomena of American ginseng(Panax Quinquefolium L.).The results obtained may be summarized as follows.
1. The wall layer of anther is regulatively formed i.e., hypodermal archesporium is divided periclinally into two parts, forming the primary parietal cell outside and the sporogenous cell inside. The primary parietal cell is divided into two secondary parietal layer through the process of one division, the outside secondary parietal cell periclinally forms endothecium outside and middle layer inside.
And the inside secondary parietal cell grow to tapetum without cytokimesis. That is of dicotyledonous type.
2. The type of microspore tetrad is tetraheral.
3. The division of sperm nucleus within the pollen grain was not observed.
4. Syncarpous gynoecium has central marginal placenta with two carpels and two loculi.
5. Two ovules grow in a carpel and one of them elongates toward upright and the other downward.
6. The angles formed between the ovarian axis and the nucellar axis are measured so as to determine the relationships between the measured angles and the growth of ovule and anther respectively.
7. Megaspore tetrad was mostly arranged to form linear type, but rarely, decussate and intermediate type was also observed.
8. Normally, the charazal end megaspore functions as the embryo sac mother cell, but very rarely micropylar end megaspore may also functions.
9. Ovule type is of anatropous.
10. Embryo sac is of polygonium type.
11. Ovule has a single integument.
12. The development of integument in rudimentary ovule is discontinued after the early stage.
13. Double fertilization is finished within 24-36 hours after pollination.
14. The first division of primary endosperm nucleus occurs immediatly after fertilization while in the zygote after 10 days.
15. The embryo of Panax Quinquefolium corresponds with that of chenopodium Bonus-henricus.
16. Endosperm nucleus is of free nuelear type.
17. Proembryonic differentiation is slightly later than the case of Korean ginseng.
18. Ovule type is the "crassinucellate".