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Volume 83, Issue 983
Displaying 1-4 of 4 articles from this issue
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Yoshio YOSHIDA1970 Volume 83 Issue 983 Pages 137-143
Published: 1970
Released on J-STAGE: October 31, 2006
JOURNAL FREE ACCESSChanges in chlorophyll and free sugar contents of Elodea leaves after detachment, and effects of nicotinamide adenine dinucleotide (NAD) and benzimidazole on the changes were investigated. NAD accelerated the loss of chlorophyll, but benzimidazole counteracted the NAD effect and maintained chlorophyll at a high level. Light was found to be necessary for the NAD acceleration of the senescence. Detachment of leaves caused an increase in the free sugar content, while treatment of the detached leaves with NAD caused a decrease. This effect of NAD was also inhibited by benzimidazole.View full abstractDownload PDF (2317K) -
Kazuo HOZUMI, Hiromitsu KIRITA1970 Volume 83 Issue 983 Pages 144-151
Published: 1970
Released on J-STAGE: October 31, 2006
JOURNAL FREE ACCESSLeaves constituting a forest canopy are well adapted to different levels of light intensity to which they are exposed at different depths within the canopy. The parameters of the photosynthetic rate-light intensity curve determined with detached leaves were found to undergo certain regular changes corresponding to the extinction of light from the surface to the bottom of forest canopy.
The canopy photosynthesis model proposed by Monsi and Saeki was elaborated taking these regularities into consideration, in order to enable a more accurate estimation of the rate of canopy photosynthesis in forests on the basis of reasonable mathematical procedure. Some biological and mathematical properties of the newly proposed model were also discussed.View full abstractDownload PDF (649K) -
Masahiko IKEMORI1970 Volume 83 Issue 983 Pages 152-162
Published: 1970
Released on J-STAGE: October 31, 2006
JOURNAL FREE ACCESSFor the elucidation of relationship between photosynthesis and calcium carbonate deposition in marine algae, the rates of calcium-45 uptake and calification were investigated. The rate of calcium-45 uptake increased in the light by two to five times greater than that in the dark. A remarkable calcification gradient from the marginal part to the basal part was observed in the vegetative frond of Padina japonica. In the sporogenous frond, the uptake rate was greatly reduced even in the light especially at the sporogenous part. The amount of calcium taken up by calcareous algae was from ten to a hundred times larger than that by non- calcareous algae, while no significant difference was observed among the rates of their photosynthesis. In all species of calcareous and non-calcareous algae so far used in this work, the inhibitors of carbonic anhydrase caused a marked depression in the uptake rate even in the light, and the inhibitors of photosynthesis also made a cessation of measurable increase. Among four fractions from the algal fronds in which calcium-45 was incorporated, acid-soluble fraction which consists mainly of calcium carbonate showed higher radioactivity, while such fractions as ethanol soluble and alkali soluble ones contained lesser activities. Moreover, it was found that when the experiments were carried out in the light, the radioactivity incorporation into the acid-soluble fraction became greater as compared with that into the other fractions.View full abstractDownload PDF (1340K) -
Yoko KISE, Seizi TATUNO1970 Volume 83 Issue 983 Pages 163-172
Published: 1970
Released on J-STAGE: October 31, 2006
JOURNAL FREE ACCESSCytological studies were made on 2 species and 3 varieties belonging to the genus Atrichum grown in Japan. The structural sex chromosomes were found in A. undulatum var. minus and A. yakushimense. The X and Y of the two taxa were the longest heterochromosomes (H) of the complement in both female and male gametophytes. No difference was observed between the X and Y in size and shape at the metaphase of mitosis, but the heterochromatic part of Y is larger than that of X at prometaphase.
The karyotypes of the Atrichum studied can be formulated as follows:
Atrichum undulatum
var. minus …… {_??_K(n)=7=V(H, X)+3V+2J+m(h) _??_K(n)=7=V(H, Y)+3V+2J+m(h)
var. undulatum …… _??_K(n)=14=V(H, X)+V(H, Y)+6V+4J+2m(h)
var. haussknechtii ……_??_ K(n)=21=2V(H, X)+V(H, Y)+9V+6J+3m(h)
A. yakushimense …… {_??_K(n)=7=V(H, X)+3V+2J+m(h) _??_K(n)=7=V(H, Y)+3V+2J+m(h)
A. spinulosum ……_??__??_K(n)=7=V(H)+3V+2J+m(h)
The relations between the chromosome constitution and the sex in three varieties of A. undulatum complex are as follows; _??_A+X, _??_A+Y (var. minus), _??_2A+X+Y (var. undulatum) and 3A+2X+Y (var. haussknechtii). The sex in A. undulatum complex is determined by the sex chromosomes X and Y.View full abstractDownload PDF (2646K)
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