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Volume 44 (1969)
- Issue 6 Pages 341-
- Issue 5 Pages 275-
- Issue 4 Pages 193-
- Issue 3 Pages 117-
- Issue 2 Pages 57-
- Issue 1 Pages 1-
Volume 44, Issue 5
Displaying 1-7 of 7 articles from this issue
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Y. YAN1969 Volume 44 Issue 5 Pages 275-284
Published: 1969
Released on J-STAGE: May 21, 2007
JOURNAL FREE ACCESSA comparative study was made of the kinetics of inactivation of Escherichia coli strain 15 T-A-U-by ultraviolet (u. v.) and by the decay of incorporated 32P atoms among different physiological states. The bacteria in logarithmic phase in the glucose medium were more sensitive to u. v. than those growing at lower rates in the succinate, aspartate and proline media. Having grown under the absence of protein synthesis, the bacteria became strikingly resistent to u. v. and had the same survivals irrespective of growth media. The u. v. sensitivity of 5-bromouracil (BU) substituted bacteria also varied reflecting the growth medium in which they incorporated BU into DNA. The sensitivity of the bacteria to the decay of 32P atoms that had been uniformly incorporated was not substantially altered by the change in growth conditions. A considerable fraction of 32P pulse-labeled cells in the succinate medium escaped from inactivation though the majority of those pulse-labeled in the glucose medium were susceptible. The relationship between the sensitivity of the bacteria to u. v. and 32P decay and the number of chromosomes per cell and DNA replication cycle, and also the character of the lethal damage induced by u. v. and 32P decay are discussed.View full abstractDownload PDF (947K) -
EIZO MAEDA1969 Volume 44 Issue 5 Pages 285-289
Published: 1969
Released on J-STAGE: May 21, 2007
JOURNAL FREE ACCESSThe nuclear modification for prolonged subculture was studied with rice callus tissues using three varieties.
The nuclear size of Tan-ginbozu callus tissues, a dwarf variety in Japonica type, increased from 6μ to 7μ in their mean diameter after about one year of subculture. The cells having the giant nucleus above 11μ were observed. The elucidation of the histological steps of the nuclear modification ascertained that the enlarged and vacuolated cells containing the giant nucleus are enveloped with the cells having nuclei of ordinary size. However, the cells of Te-Tep and Konansen, tall varieties in Indica type, retained their characteristic morphology of nuclei for prolonged periods of culture.View full abstractDownload PDF (2140K) -
PYUSO TANAKA1969 Volume 44 Issue 5 Pages 291-296
Published: 1969
Released on J-STAGE: May 21, 2007
JOURNAL FREE ACCESSThe transformation of heterochromatic property to an euchromatic property-Deheterochromatinization-was found in certain chromosomes of Spiranthes sinensis (2n=30). The deheterochromatinized chromosomes are genetically homologous to their progenitorial chromosomes which have a small heterochromatic segment. The deheterochromatinization has a genetic influence in increasing the size of organs.View full abstractDownload PDF (2686K) -
II. EFFECT OF GENETIC BACKGROUND ON MIGRATORY BEHAVIOR OF DROSOPHILA MELANOGASTERTAKASHI NARISE1969 Volume 44 Issue 5 Pages 297-302
Published: 1969
Released on J-STAGE: May 21, 2007
JOURNAL FREE ACCESSExperiments were conducted to estimate the migratory behavior of D. melanogaster under the genetically heterogeneous conditions. Five wild, five vestigial and four kinds of F1 hybrid strains between wild strains were used.
The migratory activity of the vestigial strains was promoted by the wild ones except in a few cases, while the wild type strains were reduced in activity when mixed with vestigial strains. Furthermore, the migratory activity of either wild type or vestigial strains increased when mixed with strains of different genetic background.
From the results of cross-experiment, it was found that the larger the difference between genetic background of the two strains in a mixture, the more intense the stimulation effect on migratory activity appears.View full abstractDownload PDF (552K) -
B.B. SHAHI, HIROKO MORISHIMA, H.I. OKA1969 Volume 44 Issue 5 Pages 303-319
Published: 1969
Released on J-STAGE: May 21, 2007
JOURNAL FREE ACCESSA total of 541 strains belonging to 21 Oryza species were observed for leaf-blade isozymes of peroxidase and acid phosphatase, and 147 of them belonging to O. perennis and O. sativa for esterase isozymes in addition. The species markedly differed in zymogram variability. Widely distributed wild species generally had a large number of various zymograms, while localized wild species as well as cultivated ones showed limited variation. Though certain species had zymograms peculiar to them, identification of species by zymogram seemed to be difficult on account of wide variations within the species. The data were treated by the technique of pattern analysis to obtain an integrated picture. In the scatter diagrams obtained, closely related species were placed near one another but the distribution areas of their strains overlapped, suggesting that genes specifying the isozymes might be commonly distributed among different species. In both peroxidase and acid phosphatase, the cultivated species, sativa and glaberrima, had no zymograms of their own, as their zymograms, two for each, were present among those of their respective wild progenitors, Asian perennis and breviligulata. The two zymograms of sativa varieties represented the Indica and Japonica types, respectively. However, sativa varieties showed 19 different zymograms of esterase, the Indica and Japonica types differing in the frequencies of those peculiar to sativa.View full abstractDownload PDF (1340K) -
B. B. SHAHI, Y. E. CHU, H. I. OKA1969 Volume 44 Issue 5 Pages 321-328
Published: 1969
Released on J-STAGE: May 21, 2007
JOURNAL FREE ACCESSEight strains belonging to Oryza sativa and O. perennis (Asian form) were intercrossed, and the hybrid plants were observed for peroxidase isozymes of the leaf blades by starch-gel electrophoresis method. Band 4C was found to be specified by an active gene, Pe4C. Bands 2A and 4A were specified by allelic genes, Pe2A and Pe4A, respectively. Their heterozygotes produced a hybrid dimer band, 3A, between 2A and 4A. Further, diallel crosses were made among ten plants randomly chosen from a population of O. perennis. The data suggested that there might be a regulatory gene, R4C, repressing band 4C. The loci of Pe4C, R4C and Pe2A/Pe4A appeared to be independent of one another.View full abstractDownload PDF (1133K) -
K. VIJAYA BAI, M. L. MAGOON, R. KRISHNAN1969 Volume 44 Issue 5 Pages 329-338
Published: 1969
Released on J-STAGE: May 21, 2007
JOURNAL FREE ACCESSA detailed comparative cytomorphic study of the diploid Ipomoea biloba Forsk. (2n=30) and a naturally-occurring tetraploid form (2n=60) was made. The extent of morphological differences between the two chromosomal types have been presented and discussed. These differences relate to leaf shape and size, pollen size and length of seed coat hair. The course of microsporogenesis was investigated from pachytene stage onwards in both the taxa. Based on these data and their geographical distribution, the mode of origin of the tetraploid taxon and its relationship to the diploid was considered. The close similarity in their exomorphic characters, presence of both the diploid nucleolar chromosomal types in tetraploid and the sympatric distribution of the two taxa are advanced as evidences in favour of the direct role played by diploid biloba in the origin of the tetraploid taxon. However, in view of the prevalence of preferential pairing, low multivalent frequency and high fertility, a segmental allopolyploid origin seems probable.View full abstractDownload PDF (2425K)
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