The Japanese Journal of Genetics
Online ISSN : 1880-5787
Print ISSN : 0021-504X
ISSN-L : 0021-504X
Volume 11 , Issue 6
Showing 1-9 articles out of 9 articles from the selected issue
  • Naomasa Shimotomai
    1935 Volume 11 Issue 6 Pages 297-301
    Published: 1935
    Released: April 04, 2007
    JOURNALS FREE ACCESS
    1. Bei den 8 Arten von Potentilla, nämlich P. aurea, P. nevadensis, P. hirta, P. intermedia, P. levieri, P. gelida, P. degeni und P. chrysantha, kommt die apomiktische Entwicklung der Samen vor. Bei diesen Arten gaben die kastrierten Blüten keine Samen. Aber wenn man die Narben der kastrierten Blüte mit Pollen anderer Art bestäubt, so entwickeln sich die guten Samen. Die Pflanzen, die aus solchen Samen gekeimt sind, sind keine Bastarde, sondern sind je in allen Merkmalen ganz identisch mit der Mutterpflanze.
    2. Um die Ursache der apomiktischen Entwicklung bei dieser Gattung zu erklären, habe ich Potentilla hirta, eine der obigen 8 Arten, zytologisch untersucht. Bei der ersten Kernteilung der Meiose in der Embryosack-mutterzelle dieser Art treten 28 Chromosomen auf. Diese Chromosomenzahl ist die zygotische Chromosomenzahl derselben. Auch bei der zweiten Kernteilung der Meiose in E. M. Z. kommt dieselbe Chromosomenzahl zum Vorschein. Bei dieser Art findet also keine Reduktion der Chromosomenzahl statt, was die Entstehung der Eizelle mit diploider Chromosomenzahl zur Folge hat. Tritt der Pollenschlauch in den Embryosack ein, so beginnt die Eizelle ohne Vereinigung des Spermakerns sich zu entwickeln. Bei diesem Falle müsste der Pollenschlauch der Eizelle den Reiz geben, der für die Entwicklung derselben notwendig sein soll.
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  • Daigoro MORIWAKI
    1935 Volume 11 Issue 6 Pages 302-307
    Published: 1935
    Released: April 04, 2007
    JOURNALS FREE ACCESS
    1. A new mutant crumploid (cl) appeared in Drosophila ananassae from a stock of ct. The gene of cl is sex-linked recessive with a complex expression affected by certain modifiers.
    2. The degree of the expression of cl seems to vary from false normal to crumploid with lethal effect. In the male the expression is reduced considerably, resulting in excess of males.
    3. There is a linear correlation, rough as it is, between the frequency of crumploid in the female and that in the male.
    4. The modifiers are believed to be positive and that they could be made to accumulate by means of selection.
    5. The locus of cl is 91.8±, situated very closely to ct in the X-chromosome.
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  • FURTHER STUDIES ON CHROMOSOME NUMBERS
    Isamu UCHIKAWA
    1935 Volume 11 Issue 6 Pages 308-313
    Published: 1935
    Released: April 04, 2007
    JOURNALS FREE ACCESS
    1. The author could determine the chromosome numbers of Japanese bamboo of 8 genera including 13 species as shown in the preceeding table.
    2. According to the results of observations of this study together with the author's previous paper (Uchikawa 1933), Yamaura's paper (Yamaura 1933) and Hunter's paper (Hunter 1934), it is certain that most species of Japanese bamboo have the chromosome number of 2n=48, and only a few 2n=54, 2n=72. The latter number is found only in Bambua species. The numbers 48, 54 and 72 are multiples of 6. It is, therefore, assumed that the basic chromosome number of bambuseae is 6.
    3. Phyllostachys reticulata KOCH is sterile. It has normal 24 bivalents in P.M.C., and its pollen grains and ovaries are normally developed. As it is propagated asexually, the phenomenon of the sterility in Phyllostachys reticulata KOCH can be explained by self-incompatibility.
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  • Y. Yamazaki
    1935 Volume 11 Issue 6 Pages 314-315
    Published: 1935
    Released: April 04, 2007
    JOURNALS FREE ACCESS
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  • N. Shinke
    1935 Volume 11 Issue 6 Pages 315
    Published: 1935
    Released: April 04, 2007
    JOURNALS FREE ACCESS
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  • T. Toyohuku
    1935 Volume 11 Issue 6 Pages 316-317
    Published: 1935
    Released: April 04, 2007
    JOURNALS FREE ACCESS
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  • T. Ikemi
    1935 Volume 11 Issue 6 Pages 318-319
    Published: 1935
    Released: April 04, 2007
    JOURNALS FREE ACCESS
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  • Kotaro KARASAWA
    1935 Volume 11 Issue 6 Pages 320
    Published: 1935
    Released: April 04, 2007
    JOURNALS FREE ACCESS
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  • Y. Yamamoto
    1935 Volume 11 Issue 6 Pages 321-329
    Published: 1935
    Released: April 04, 2007
    JOURNALS FREE ACCESS
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