Shokubutsugaku Zasshi
Online ISSN : 2185-3835
Print ISSN : 0006-808X
ISSN-L : 0006-808X
Volume 82, Issue 967
Displaying 1-5 of 5 articles from this issue
  • Influences of Localized X- or Gamma-irradiation
    Kiyomi WADA
    1969 Volume 82 Issue 967 Pages 1-5
    Published: 1969
    Released on J-STAGE: October 31, 2006
    JOURNAL FREE ACCESS
    Acute moderate doses of ionizing radiations given to the whole plant exert a pronounced influence on the initiation and development of flower primordia in Pharbitis seedlings1, 2). However, they had no effect when the irradiation was restricted to the cotyledons or cotyledonary petioles, or when the plumule was shielded from the radiation by a lead bar. This implies that the ionizing radiationss directly inhibit the initiation and development of flower primordia in the plumule.
    Very strong X-rays (40kR-100kR) applied to the cotyledonary petioles inhibited flowering when the radiation was given 12-16 hours after the beginning of the dark period, the time when the floral stimulus might be passing through the petiole.
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  • Analysis of Production Processes of Young Abies Stand Based on the Carbohydrate Economy
    Makoto KIMURA
    1969 Volume 82 Issue 967 Pages 6-19
    Published: 1969
    Released on J-STAGE: October 31, 2006
    JOURNAL FREE ACCESS
    The economy of carbohydrates was analysed in relation to the growth and the dry matter production of Abies stand about 15 years old in the subalpine zone of Mt. Shimagare, Nagano Prefecture, central Japan. Seasonal changes of sugar, starch and hemicellulose contents in needles, branches, stems and roots were pursued. Combining these results with those of seasonal growth and respiratory activity of each organ, balance sheets of matter economy of the community were constructed.
    Three phases were recognized in the annual cycle of matter economy of the community. In the 1st phase, May and the early half of June, the plants did not
    show any growth, and about a half of the matter produced by photosynthesis was accumulated in the old organs and the rest was consumed by respiration. In the 2nd phase, from mid-June to late August, new organs grew rapidly depending partly on the conversion of carbohydrates reserved in the old organs. In the 3rd phase, from September to late November, most of the photosynthetic products were reserved for the use in the next year.
    From these analyses, the role of the evergreen leaves in the habitat of severe winter was elucidated as follows; a) they play a role as the reserve organ of large capacity in winter, and b) they recover rapidly their photosynthetic activity in early growing season to accumulate reserves, in addition to those of the winter season, before buds break from dormancy. These reserves guarantee the subsequent rapid growth of new organs in early summer.
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  • Nobuo NOMOTO, Toshiro SAEKI
    1969 Volume 82 Issue 967 Pages 20-27
    Published: 1969
    Released on J-STAGE: October 31, 2006
    JOURNAL FREE ACCESS
    An improvement of the half-leaf method was made by the application of steaming to conducting cells to stop translocative outflow of assimilates. The improved method was used for obtaining the diurnal change of the photosynthetic accumulation, translocative outflow and respiratory loss of matter in fully exposed leaves of sunflower and maize plants. The maximum rates of photosynthesis obtained, 28mg dry matter/dm2/hr for sunflower and 40mg for maize were comparable to those reported recently by the improved gasometric leaf-chamber methods. The photosynthetic activity proceeded roughly in parallel with the change of light intensity, and the variation of photosynthetic CO2-fixation was closely followed by that of translocation; hence moat of the translocative outflow of assimilates occurred in daylight hours.
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  • Masahiko KIKUCHI, Kozo HAYASHI
    1969 Volume 82 Issue 967 Pages 28-31
    Published: 1969
    Released on J-STAGE: October 31, 2006
    JOURNAL FREE ACCESS
    By the use of broad beans (seeds of Vicia faba L.), the distribution of thiamine and its phosphates in germs and seedlings was investigated at various growing stages. The results may be summarized as follows: Thiamine in dormant seeds is entirely in a free state, and concentrated mostly in germ axis (c.f., Table 1.). When germ axes, which are attached to or separated from the seeds, are soaked with water, free thiamine contained in them disappears and, in turn, thiamine phosphate comes into appearance, whereas this is not the case in soaked cotyledons lacking germ axes (Table 1 and 2). When isolated germ axis is soaked with water, the phosphate of thiamine that appears is not the diphosphate, but exclusively triphosphate alone (Table 3). Thiamine triphosphate can be detected in germ axis at a primary step of seed germination, while only the diphosphate at later stages (Table 4).
    Consequently, it is surmised that thiamine triphosphate may act as a “sparkling substance” for the initiation of germinating process. In this connection, the recent finding described by T. Yusa2, 3) is quite provocative, since the terminal phosphate group of thiamine triphosphate can be readily transferred to ADP resulting in the recovery of ATP.
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  • Karyotyps of H. kiyosumiensis, H. sieboldiana, H. hypoleuca and H. caput-avis
    Kenichiro KANEKO
    1969 Volume 82 Issue 967 Pages 32-39
    Published: 1969
    Released on J-STAGE: October 31, 2006
    JOURNAL FREE ACCESS
    The chromosome numbers of the four species (Hosta kiyosumiensis, H. sieboldiana, H. hypoleuca and H. caput-avis) were 2n=60. The karyotypes of these species were as follows: the 60 chromosomes were in 30 pairs, which could be classified into the three groups of four pairs of large chromosomes, two pairs of medium ones, and 24 pairs of small ones. Details in each of the three groups differed according to species.
    In the clone of H. sieboldiana obtained in Kyoto, the karyotype was the one original to this genus: four pairs of large chromosomes with terminal or subterminal primary constriction, and two pairs of medium chromosomes of which one had satellites. In the clone of the same species from Hirosaki, however, the karyotype differed from the above in that there were no satellites. In H. caput-avis, karyotypes differed according to the clones used, variation being found in the positions of primary constriction in the large and medium chromosomes.
    Of the four pairs of large chromosomes of H. kiyosumiensis and H. caput-avis, one pair were satellite chromosomes with submedian primary constriction. It can probably be inferred that these chromosomes derived from large chromosomes with terminal primary constriction.
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