植物学雑誌
Online ISSN : 2185-3835
Print ISSN : 0006-808X
ISSN-L : 0006-808X
48 巻 , 575 号
選択された号の論文の4件中1~4を表示しています
  • T. Nakai
    1934 年 48 巻 575 号 p. 773-792
    発行日: 1934年
    公開日: 2007/05/24
    ジャーナル フリー
  • Hiroshi Hara
    1934 年 48 巻 575 号 p. 793-813
    発行日: 1934年
    公開日: 2007/05/24
    ジャーナル フリー
  • Tadamasa Miduno
    1934 年 48 巻 575 号 p. 814-822
    発行日: 1934年
    公開日: 2007/05/24
    ジャーナル フリー
    1. Das Kernstück ist sichelförmig. Als Ausnahme wurden Kernstücke, die doppelt so lang und zwei drittel so lang wie die gewöhnlichen Kernstücke sind, gefunden.
    2. Die Form des Plasmastückes ist unbeständig. Eins läuft entlang der konkaven Seite des Kernstückes von der vorderen bis zur hinteren Spitze des Kernstückes. Ein anderes läuft von der vorderen Spitze bis zum mittleren Teil des Kernstückes, und am hinteren Teil des Kernstückes haftet das zweite, runde Plasmastück an.
    3. Die Zahl der Zilien ist gewöhnlich zwei. Ausnahmsweise wurden fünf Spermatozoiden mit drei Zilien und ein Spermatozoid mit vier Zilien gefunden. Die Spitze der Zilien ist zweifach gegabelt.
    4. Beim Riesenspermatozoid, sind die Zilien im Verhältnis zum Kernstück sehr kurz.
  • Dyuhei Sato
    1934 年 48 巻 575 号 p. 823-846
    発行日: 1934年
    公開日: 2007/05/24
    ジャーナル フリー
    1. Yucca recurvifolia (n=30) has five large bivalents and twenty-five small bivalents as has Yucca flaccida (cf. O'MARA 1931). The chiasma frequencies of large chromosomes at the diplotene stage, and at the early and late diaphases are 4.34, 3.07 and 2.48 respectively, while those of small chromosomes at the diplotene stage and at the early diaphase are 2.06 and 1.33 respectively. Evidently, the chiasma frequency is not a direct function of the chromosome length, as in Stenobothrus, Chorthippus, Hyacinthus amethystinus, Scilla and Urginea. The terminalisation is complete at the early diaphase in small chromosomes in Yucca, but incomplete at the late diaphase in large chromosomes.
    2. Scilla peruviana (2n=16) has one pair of long chromosomes, four pairs of medium chromosomes and three pairs of short chromosomes. These types of bivalent may be readily recognized during the diplotene and metaphase stages of meiosis, so this provides a favourable material for an analysis of the chromosome complement. The observations made at the prophase of Scilla give results similar to those on the chiasma behaviour in Yucca. One of the short bivalents was attached to the nucleolus and a satellited bivalent was found at diaphase.
    3. Urginea scilla 2n=40(4b) has eight large chromosomes and thirty-two small chromosomes. The results of the observations made on the prophase chromosomes of Urginea resemble those found with Yucca except as regards the formation of tetravalents in the former. Tetravalent configurations were traced at both the diplotene and diaphase stages. Terminalisation of chiasmata was ascertained in both large and small tetravalents. The chromosome configurations were clearly explained by the pairing blocks theory (cf. DARLINGTON and MATHER 1932; STONE and MATHER 1932).
    4. The pairing of chromosomes before the split is conditioned by chromomeres which may pair by their individual homology and after the split it is conditioned by chiasmata, and the chiasma frequency and distribution are influenced by genetical genes.
    5. The reduction in the number of chiasmata may be chiefly due to terminalisation, for apparent chiasmata open out between the pachytene and diplotene stages and ‘break and join’ of crossed chromatids at a chiasma (SAX 1930, 1932 a) does not occur.
    6. The position of the spindle fiber attachment, chromosome length and interference were chiefly discussed with reference to chiasma behaviour. The symmetrical relation of the chromatids in bivalents with two chiasmata in Paeonia, Larix, Tsuga and Allium is explained on the BELLING'S chiasma theory (1933) with regard to interference.
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