The Japanese Journal of Genetics
Online ISSN : 1880-5787
Print ISSN : 0021-504X
ISSN-L : 0021-504X
Volume 31, Issue 3
Displaying 1-5 of 5 articles from this issue
  • III. THE BREEDING SYSTEM OF TRILLIUM KAMTSCHATICUM PALL. IN SOME NATURAL POPULATIONS
    Takashi NARISE
    1956 Volume 31 Issue 3 Pages 65-81
    Published: 1956
    Released on J-STAGE: May 21, 2007
    JOURNAL FREE ACCESS
    The problem of breeding systems, which bears fundamental importance in the course of study on the dynamics of genetical changes among the populations, has been investigated by many workers since the beginning of this century. The Hardy-Weinberg law established in the year 1908 is the most fundamental principle in this problem. It has an important meaning in respect to organic evolution as was pointed out by Dobzhansky (1951, pp. 53). In this paper, the breeding system of T. kamtschaticum, is studied applying this law with reference to the types of differential segments of chromosomes in several populations found in northern Japan.
    Though there were many kinds of types in each chromosome pair as shown in Appendix Tables and Table 2, they could be classified into two groups: A and nonA. Then the Hardy-Weinberg law was applied regarding A and nonA as a pair of alleles. Based on the results of χ2-test for the Hardy-Weinberg law, it was concluded that the breeding of T. kamtschaticum in almost all the natural populations was random.
    The values of χ2-test in Sr and Srr-N, however, showed significant deviation from the Hardy-Weinberg law. These deviations were tentatively attributed, in Sr, to predominance of inbreeding, and in Srr-N, to the formation of a subgrouping in this population due to some ecological conditions. Acknowlegement The writer wishes to express his thanks to Mr. Masataka Kurabayashi for many valuable guidances and suggestions throughout this study, to Mr. Motoo Kimura for helpful and kind advises with statistical method and to Professor Hajime Matsuura and Professor Tsutomu Haga for several suggestions.
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  • Goichi NAKAJIMA
    1956 Volume 31 Issue 3 Pages 82-86
    Published: 1956
    Released on J-STAGE: May 21, 2007
    JOURNAL FREE ACCESS
    1. In this investigation, the F1 plant raised between Triticum dicoccum var. atratum and Secale Vavilovii was studied cytogenetically.
    2. 2974 spikelets on 128 spikes of T. dicoccum var. atratum were pollinated with the pollen of S. Vavilovii, and 25 kernels were obtained. Each of these kernels was sown in separate pots, and from them only one F1 hybrid was raised. The percentage of the F1 individual to the number of all the pollinated spikelets was 0.0336 percent. In this investigation, 8 combinations of hybridization between Emmer wheat (8 species) and S. Vavilovii were tried, but in 7 combinations among them no F1 plant was obtained (Table 1).
    3. Almost all the external characters of the F1 plant, except one or two, resembled more closely to T. dicoccum var. atratum than being intermediate between the parents. Colour of spike was purplish black, and almost looks like that of T. dicoccum var. atratum. The spikelet of F1 was not so brittle at the ripening stage as in the F1 T. dicoccum var. atratum× S. cereale.
    4. The number of chromosomes was counted to be 21 as 2n at the heterotypic division in PMC's of the F1 and it corresponds to the sum of the reduced chromosome numbers of the parents. At heterotypic metaphase in PMC's of the F1 plant, 0_??_4 bivalents and 13_??_21 univalents were observed (Table 3). The frequency of the bivalents in PMC's is shown in Table 3, and the case of zero appears to be the mode. Stick-shaped bivalents formed by 2 elements of equal size conjugated end to end were generally observed, and as a rare case, a ring-shaped bivalent in which two equal sized elements closely conjugated was also observed (Table 3). Those bivalents up to 4 may probably be made by autosyndesis between the chromosomes of AB genomes of T. dicoccum var. atratum. used as the mother plant. No tri-and tetravalent were observed.
    5. At heterotypic anatelophase of PMC's the chromosomes were distributed to the opposite poles 0:21_??_10:11, and the distribution 10:11 appeared to be the mode. (Table 4).
    6. At heterotypic metaphase of PMC's univalents were normally scattered in the spindle, but in some cases the formation of equatorial or semi-equatorial plate was observed, and consequently non-conjugation and the formation of restitution nucleus were rarely observed. Almost all the anthers of F1 were not opened and the pollen grains showed almost sterile, but on rare occasions, some anthers were opened and a few kernels (21) were obtained in natural selfing.
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  • Taro JINNO
    1956 Volume 31 Issue 3 Pages 87-88
    Published: 1956
    Released on J-STAGE: May 21, 2007
    JOURNAL FREE ACCESS
    The chromosome numbers in somatic cells of six species of Lysimachia are determined by the writer as follows: L. clethroides 2n=24, L. acroadenia 2n=24, L. Fortunei 2n=24, L. japonica 2n=20, L. mauritiana 2n=20 and L. sikokiana 2n=60. They can be devided into two groups with respect to the basic chromosome number: one is the group having chromosome number b=12, while the other is the group with b=10. The size and shape of the chromosomes in the species belonging to the former are generally similar each other, while those of latter are different from species to species.
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  • VIII. The karyotypes of six species in four genera
    Masahide KURITA
    1956 Volume 31 Issue 3 Pages 89-92
    Published: 1956
    Released on J-STAGE: May 21, 2007
    JOURNAL FREE ACCESS
    1. The karyotypes of six species studied in this work can be represented as follows:
    Pulsatilla cernua K(2n)=16=8Am+2Bsm+2Cst1+2tCst2+2tDst
    P. nipponica K(2n)=32=16Am+4Bsm+8Cst+4tDst
    Anemone debilis K(2n)=16=10Am+2Bst+2Cst1+2Cst2
    A. flaccida K(2n)=14=12Am+2tBst
    Hepatica triloba K(2n)=14=12Am+2tBst
    Caltha fistulosa K(2n)=32=4Asm+4Bsm1+4Bsm2+4Cst1+4Cst2+4Dst+4Est+4Fm
    2. The haploid chromosome sets of Anemone flaccida and Hepatica triloba are closely similar to each other, each of them differing considerably from the haploid set of Anemone debilis which resembles the basic set of Pulsatilla-species.
    3. The basic chromosome set of Caltha fistulosa is somewhat similar to the haploid set of Trollius Riederianus var. japonicus (Kurita 1955b) excepting that, in the latter, there occur no chromosomes resembling the g-and the h-chromosomes (Fig. 5) of the former in morphology.
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  • Michiharu SEGAWA
    1956 Volume 31 Issue 3 Pages 93-96
    Published: 1956
    Released on J-STAGE: May 21, 2007
    JOURNAL FREE ACCESS
    1) Die Chromosomen von Anthoceros laevis L., einer Art des Lebermooses, wurden bei der Mitose und Meiose untersucht.
    2) Eine neue Färbungsmethode wurde zur Beobachtung der Chromosomen benutzt, weil die Zellen dieser Art die grosse Menge der Öltropfen enthalten: Fixierung mit Carnoy's Lösung (abs. Alk. 3: Eisessigsäure 1) 1-3 Stunden; Im Gemisch (Eisessigsäure 45cc+2% FeCl3•6aq. 55cc) 2-12 Stunden; In 45% Essigsäure 2 Minuten; Färbung mit Schneider's Essigsäure-Karmin 2-3 Minuten.
    3) Die Chromosomenzahlen sind n=6, 2n=12; Der Karyotypus ist K=V(H)+2V+2J+m(h).
    4) Das heterochromatische H-Chromosom dieser Art ist das Nukleolus-Chromosom. Das heterochromatische h-Chromosom ist aber das Nukleolinus-Chromosom, das im Nukleolus als ein dunkel farbiges Körperchen bleibt.
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