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국내연구정보 (Domestic information) |
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| Internal Changes and Germinability during Seed Maturation |
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| 글쓴이 : 관리자
날짜 : 09-01-24 12:38
조회 : 14442
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Studies on the Internal Changes and Germinability during the Period of Seed Maturation of Pinus koraiensis Sieb. et Zucc. <Jour. Kor. For. Soc. 21:1-34 1974> Kyung-Hyun Min
External and internal changes were investigated in cone structure and content of water, sugar, fat and protein during the period of seed maturation. The results were summarized as follows:
1. Male flower
1) Pollen-mother cells occurred as a mass from late April to early May, and formed pollen tetrads through meiosis early to middle May. Pollen with simple nucleus reached maturity in late May. 2) Stamen number of a male flower was almost the same as the scale number of cone and was 69-102 stamens. One stamen included 5800-7300 pollen. 3) Pollen shape was circular or elliptical, including two air-sacs, each of which was 80-91 µ in length, and each pollen had cuticular exine and cellulose intine. 4) Pollen germinated within 68 hours at 25℃ in the medium of pH 6.0, 2% sugar and 0.8% agar.
2. Female flowers
1) Ovuliferous scales grew rapidly from late April, and differentiation of ovules began in early May. Embryo-sac-mother cells produced tetrads through meiosis in middle May, and flower in late May. 2) The pollinated female flowers showed repeated divisions of embryo-sac nucleus, and a great number of free nuclei formed a mass up to the end of current winter. Morphogenesis of isolation in the mass structure took place from the middle of March and formed albuminous bodies of aivealus in early May.
3. Formation of pollinators and embryos
1) Archegonia produced archegonial initial cells from middle to late April, and pollinators were produced from late April to early May. 2) After pollination, oespore nuclei were seen to divide in late May to form a layer of suspensor from the diaphragm from early to middle June. Thus this happened to show four pro-embryos. The organ of embryos began to differentiate one pro-embryo and reached perfect maturation in late August.
4. The growth of cones
1) In the current year of flowering, young strobilii grew during the period from the middle of June to the middle of July, and did not grow after the middle of August. Strobilii grew 1.6 times longer in length, 3.3 times thicker in diameter and about 22 times heavier than female flowers at the time of flowering. 2) The cones at the adult stage grew 7 times longer in length and 12-15 times wider in diameter than those of strobili just after flowering. 3) A cone had 96-133 scales, of which 69-80 % established full seeds. A cone was 11-13cm long, 5-8cm wide and 160-190g in weight; and its seed number was 90-150, of which 8-15% were empty.
5. Formation of seed-coats
1) The layers of outer seed-coat showed the thickest width of 703µ in the middle of July. At the adult stage, it lessened to 550-580µ because of decreasing moisture content. Then a horny and cortical tissue of outer coats became differentiated. 2) The outer seed-coat of mature seed formed epidermal cells of 3-4 layers and the stone cells of 16-21 layers. The interior part of it became a parenchyma layer including 1 or 2 rows. 3) Inner seed-coat formed 2 months earlier than the outer seed-coat in the middle of May, having the largest width of 667µ. At the adult stage it lessened to 80-90µ.
6. Change in moisture content
After pollination, moisture became gradually reached the maximum content in the early June and became markedly decreased in the middle of August. At the adult stage it showed 43~48% in cone; 23~25% in the outer seed-coat; 32~37% in the inner seed-coat; 23~26% in the inner seed-coat, female gametophyte, and embryo; 21~24% in the female gametophyte and embryo; and 36~40% in the embryo.
7. The constituent composition of seed
1) Fat content became gradually increased after the early May and at the adult stage it occupied 65~85%, which is higher than that in walnut and palm. Fat content was 78.8% in embryo, while 57.0% in female gametophyte. 2) Sugar content only just after pollination became greatly increased in the case of reducing sugar, while non-reducing sugar became increased from the early June. 3) Crude protein content became gradually increased after the early May, and at the adult stage it became 48.8%. Female gametophyte included more protein than embryo.
8. Germination test
The optimum collection period of Pinus koraiensis seeds for propagation turned out early September through the germination tests, that is reduction-method and embryo culture. Seeds tested were taken at the interval of 7 days from the middle of July to the middle of September.
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