CYTOLOGIA
Online ISSN : 1348-7019
Print ISSN : 0011-4545
Volume 11 , Issue 1
Showing 1-10 articles out of 10 articles from the selected issue
  • G. A. Lewitsky
    1940 Volume 11 Issue 1 Pages 1-29
    Published: October 10, 1940
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    1. Out of a total of 491 investigated plants in the progeny of Crepis capillaris X-rayed during the seedling stage 84, or 17.1 per cent, proved to deviate from the normal as regards their karyotype. Most of these aberrants (74) were characterized by structural chromosome changes. The data are summarized in Table 1 (p.2).
    2. In a number of cases several individuals with identically altered chromosomes arose from one mother plant, indicating their origin from a single aberrant cell of the latter, which had given rise to an entire aberrant sector or part of the mother plant.
    3. The most common types of visible cytological changes were translocations, shown by the shortening of one chromosome and the corresponding lengthening of another, and inversions, resulting in alterations in the morphology of the chromosomes concerned.
    4. All of these changes were first obtained in a heterozygous state, and afterwards produced in a hcmozygous state.
    5. In addition to balanced changes, cases of duplication were also obtained, both of whole choromosomes (all three types) and of separate parts of chromosome D, distal (of various kinds) and proximal. The latter change was also obtained in the form of a tetrasomic.
    6. Some of the investigated structural aberrants were characterized by lowered fertility. In most cases this decrease in fertility was more marked in the heterozygous state; in others-in the homozygous state. In the former this was due, presumably, to cytological reasons; in the latter-to genetical, perhaps to a lethal expression of the “position effect.”
    7. In the progeny of structural heterozygotes structurally altered homozygotes occur, as a rule, less frequently than normal plants.
    8. Among the karyotypes of pollen grains formed by structurally heterozygous aberrants normal karyotypes are, as a rule, considerably more numerous than balanced aberrant karyotypes. In two of the investigated heterozygous translocants there were formed a considerable number of pollen grains with karyotypes having an additional chromosome or part of a chromosome. The total diversity of chromosome sets of the male gametophyte reached as many as nine types.
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  • H. W. Beams, L. W. Zell, Norman M. Sulkin
    1940 Volume 11 Issue 1 Pages 30-36
    Published: October 10, 1940
    Released: March 19, 2009
    JOURNAL FREE ACCESS
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  • T. S. Raghavan, V. K. Srinivasan
    1940 Volume 11 Issue 1 Pages 37-54
    Published: October 10, 1940
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    1. The chromosome numbers of the following genera have been determined for the first time:-
    n 2n
    (1) Angelonia grandiflora C. Morr. 10 20
    (2) Angelonia cubensis var. alba 10 -
    (3) Russelia juncea Zucc. 10 -
    (4) Russelia rotundifolia Cav. 10 -
    (5) Stemodia viscosa Roxb. 21 -
    (6) Dopatrium lobelioides Benth. 7 -
    (7) Scoparia dulcis Linn. 20 -
    (8) Vandellia crustacea Benth. 21 -
    2. Details of meiosis have been worked in Angelonia grandiflora. Secondary association has been recorded.
    3. The scope and limitations of secondary association as indicating the basic number of a genus or of a family are discussed in the light of the observations made in Angelonia.
    4. The question of the basic number of the family as revealed by the investigations of previous workers is discussed in the light of the phenomenon of secondary pairing observed in the Scrophulariaceae for the first time in the present investigations, and the conclusion is reached that five is likely to be the primary basic number, and all other numbers represent different balances of this primary number.
    5. The origin of the anther sac and the tapetum is described. It becomes bi-nucleate early and remains so until its final disintegration.
    6. The pollen grains of Angelonia and Steniodia are bi-nucleate at the time of shedding.
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  • III. The Cytology of diploid Urginea indica Kunth
    T. S. Raghavan, K. R. Venkatasubban
    1940 Volume 11 Issue 1 Pages 55-70
    Published: October 10, 1940
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    A cytological examination of the diploid population of Urginea indica revealed the existence of chromosomal fragments in the somatic and meiotic cells. Variable number of fragments occur in the same individual. It is also suspected that there exist entire individuals having a definite number of fragments in addition to the usual diploid number (2n+1f; 2n+2f; 2n+3f and so on). Such individuals have not yet been isolated.
    The behaviour of fragments in meiosis has been described. It is suggested that fragments from the C1 and C2 chromosomes would persist and the fusion of gametes having these fragments would result in individuals with varying number of these bodies. The fragments from the other chromosomes tend to be lost in mitosis and meiosis. An idiogram study of complements (21, 22, 23, and 24) having fragments of the latter kind has been presented.
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  • IV. The Cytology of triploid Urginea indica Kunth
    T. S. Raghavan, K. R. Venkatasubban
    1940 Volume 11 Issue 1 Pages 71-92
    Published: October 10, 1940
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    The existence of triploidy in Urginea indica, was suspected some years ago by the senior author. Triploids were now isolated from a heterogenous wild population. The diploid and the triploid have been studied on the basis of comparative morphology. The existence of a positive correlation between gigas characters and chromosome number has been confirmed.
    A comparative study of the rate of growth of the floral scape has been made of the diploid and the triploid, and it was revealed that it is higher in the triploid than in the diploid. No discrepency was observed in respect of the time of flowering of the triploid and diploid. Both flower almost simultaneously. This is not in consonance with a few observed cases of retarded growth, exhibited by polyploid forms. The question is raised whether conclusions arrived at on the basis of the slower growth rate etc., of polyploids are to be accepted as universally true in the face of data, such as are presented in this paper and a few others, where there is no evidence for a slower rate of growth in the polyploids as compared with the diploid forms.
    Meiosis in the triploid is described in detail. All the irregularities are described, like the elimination of chromosomes, formation of micronuclei and microcells, iameiosis, formation of restitution nucleus etc. The occurrence of unequal nuclei in pollen mother cells and their independent behaviour leading to the formation of tetrads of unequal size are also described. The possible origin of the triploid is also discussed in the light of the data on hand.
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  • Bungo Wada
    1940 Volume 11 Issue 1 Pages 93-116
    Published: October 10, 1940
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    Durch Lebendbeobachtungen wurde die Einwirkung des Colchicins auf die Mitose der Staubfadenhaarzellen von Tradescantia untersucht, wobei das Verhalten der Spindelfigur nicht nur an ihrer Morphologie, sondern auch an der Veränderung ihrer Kolloidzustände kontinuierlich verfolgt wird.
    Das Colchicin wirkt unter verschiedenen Teilungselementen allein auf das Atraktoplasma eigenartig, aber auf andere and weiter auf die Lebensfähigkeit der Zelle kaum ein.
    Bei dem Verhalten des Atraktoplasmas in der Colchicinlösung ist angenommen, daß das Colchicin in der sich teilenden Zelle als oberflächenaktive Substanz wirkt and die Grenzflächenspannung des Atraktoplasmas herabsetzt. Verschiedene Veränderungen bei der C-Mitose können als Resultat der Herabsetzung der Grenzflächenspannung des Atraktoplasmas and als ihre Begleiterscheinungen erklärt weraen.
    Unter der Colchicinlösung setzt bei dem sich teilenden Kerne schon in der späten Prophase die Chromosomenverdoppelung ein, welche ohne Eintritt in die Metaphase vor sich geht.
    Ungeachtet der Veränderung des Atraktosoms bei der C-Mitose unterscheiden sich das Atraktoplasma and auch die Phragmoplast-Substanz durch eine Grenzfläche vor Zytoplasma and das erstere umgibt die zerstreuten Chromosomen. Der Abbau des Atraktoplasmas setzt parallel mit der Chromonematisierung der Chromosomen ein and das Atraktoplasma zytoplasmatisiert sich.
    Bei der Zytoplasmatisierung verflüssigt sich das Atraktoplasma, entwickelt sich schließlich zur granulenreichen, flüssigen Plasmamasse and fließt mit dem Zytoplasma der Mutterzelle zusammen.
    Zum Schluß spreche ich der Japanischen Gesellschaft zur Förderung der Zytologie für die finanzielle Unterstützung dieser Arbeit meinen besten Dank aus.
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  • I. Observations on the F1 progeny of sugar cane-sorghum hybrids
    Akira Moriya
    1940 Volume 11 Issue 1 Pages 117-135
    Published: October 10, 1940
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    1) Studies of chromosomes were made in F1 progenies of the sugar cane variety 2725 POJ crossed with Sorghum vulgare.
    2) In 2725 POJ, the chromosome number was 2n=107. Since, in the meiosis of its PMC, univalent chromosomes were observed together with bivalents, and occasionally multivalents, in the polar view of the heterotypic metaphase, we counted usually more chromosome elements than the haploid number corresponding to its somatic one. The pollen grains were completely sterile. The number of chromosomes of Sorghum vulgate was n=10.
    3) The F1 plants were classified by their external characterss into three types. The first type resembled sugar cane (normal or sugar cane type), the second was a dwarf (dwarf or terato-type), and the third an intermediate between the above two (intermediate type).
    4) The chromosome number of the normal type of F1 was, 2n=118. This number arose probably by doubling of the maternal chromosomes, so that its chromosome constitution should be given as 2C+1S. Here, C represents a haploid set of chromosomes (not genom) of sugar cane and S that of sorghum. Both the dwarf and the intermediate types of F1 showed 2n=64, their chromosome constitutions being regarded as 1C+1S. As the result of genetic inequalities, the two last-named types exhibited considerable morphological differences between them and also between different individuals of a type.
    5) In the normal type of F1, about 10 univalents were found in meiosis. which may be recognized to have come from sorghum.
    6) In the intermediate type of F1, usually 37 chromosome elements, including uni-, bi-, and sometimes multivalents, were counted in its meiosis. Of these, the number of univalents exceeded. 10, which may be owing to the fact that many chromosomes of the haploid set of sugar cane conjugated autosyndedically to form bior multivalents, and the sorghum chromosomes remained univalents. Whence, it may be concluded that 2725 POJ is, at least partially, of an autopolyploid nature.
    7) The doubling of chromosomes in the F1 of normal type, resulting in chromosome constitution 2C+1S, is probably the result of splitting of the maternal chromosomes, as pointed out by Bremer (1923, 1928).
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  • John Edgar McCroan Jr.
    1940 Volume 11 Issue 1 Pages 136-155
    Published: October 10, 1940
    Released: March 19, 2009
    JOURNAL FREE ACCESS
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  • Über das Vorkommen von haploiden Pflanzen bei Bletilla striata Reichb. f. var. gebina Reichb. f
    Tadamasa Miduno
    1940 Volume 11 Issue 1 Pages 156-177
    Published: October 10, 1940
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    1) Durch die Kreuzung Bletilla striata var. gebioa (2n=32)×Eleorchis japonica (2n=40), sind die haploiden Pflanzen (2n=16) von Bletilla striata var. gebina vielleicht durch die parthenogenetische Entwicklung and gleichzeitig auch die Bastarde (2n=36) der Elternpflanzen entstanden.
    2) Die haploiden Pflanzen haben nach 20 Jahren seit dens Säen zu blühen begonnen, sind jedoch fast vorkommen steril, die Bastarde dagegen haben nie geblüht.
    3) Die Reduktionsteilung der Mutterpflanzen (Bletilla striata var. gebina) verläuft etwas unregelmäßig. Demgemäß kommen Pollen mit verschiedenen Chromosomenzahlen vor. Selten wurden einige Univalenten gefunden.
    4) In IM and JIM der Mutterpflanzen, wurde die Verbindung, einiger Bivalenten in Zweier-, Dreier- und Vierergruppen beobachtet. Diese Erscheinung mag als “Sekundärverbindung” angesehen werden.
    5) Die Verbindung in JIM ist sehr fest and die verbundenen Chromosomen erschienen wie Bivalenten, Trivalenten oiler Tetravalenten in Kettenform.
    6) Die Reduktionsteilung der haploiden Pflanzen zeigt dieselbe Eigentümlichkeit, welche bei fast alien bisher gefundenen haploiden Pflanzen ausgedrückt ist.
    7) In IM hat der Verfasser zwei Fälle gefunden: nämlich im ersten Fall, in welchem nur Univalente d. h. 16 Univalenten vorkommen, and im anderen Fall in welchem gleichzeitig Univalenten and Bivalenten vorkommen. Die ersten Fälle sind viel seltner als die zweiten.
    8) Unter den Bivalenten gibt es zwei Arten. Eine zeigt echte Bivalenten and teilt sich normal in IM. Die andere zeigt sekundär verbundene Chromosomen, welche zu den Polen gehen ohne sich zu teilen. Bei letzterer Art findet man die Verbindung von Zweier-, Dreier- oder Vierergruppen der Chromosomen, alle in Kettenform.
    9) Die Unregelmäßigkeit der Reduktionsteilung erzeugt Pollen mit verschiedenen Chromosomenzahlen. Die erste Teilung der Pollenkörner findet in alien Pollen statt, wenn sie auch sehr wenige Chromosomen (zwei) haben.
    10) Der Verfasser hat angedeutet, daßdie sekundär verbundenen Bivalenten der Mutterpflanzen zu den Bivalenten and sekundär verbundene Chromosomen der haploiden Pflanzen gewisse quantitative Beziehungen haben. Er hofft es noch weiter zu erforschen.
    Ztmz Schluß sei mir gestattet, meinem hochverehrten Lehrer Herrn Prof. Dr. Y. SINOTÔ für seine freundliche Hinweise, Besserungs- oder Ergänzungsvorschläge an dieser Stelle meinen verbindlichsten Dank auszusprechen.
    Ebenso möchte ich der Japanischen Gesellschaft zur Förderung der Zytologie für ihre finanzielle Unterstützung meinen besten Dank aussprechen.
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  • 1940 Volume 11 Issue 1 Pages e1
    Published: 1940
    Released: March 19, 2009
    JOURNAL FREE ACCESS
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