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Volume 40 (1965)
- Issue 5-6 Pages 343-
- Issue 4 Pages 261-
- Issue 3 Pages 159-
- Issue 2 Pages 87-
- Issue 1 Pages 1-
Volume 40, Issue 5-6
Displaying 1-4 of 4 articles from this issue
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MAMORU TABATA, FUSAO MOTOYOSHI1965 Volume 40 Issue 5-6 Pages 343-355
Published: 1965
Released on J-STAGE: May 21, 2007
JOURNAL FREE ACCESS1. The growth response of maize endosperm excised from immature kernels was studied in vitro, using White's medium supplemented with yeast extract. The endosperm tissue excised 9 days post-pollination generally gave best growth.
2. Of four inbred strains (two of starchy, one of waxy, and one of sugary type endosperm) of maize tested, callus tissue was formed only in the endosperm explants from the starchy strains (S41 and S42). The excised endosperm tissues of the F1 kernels obtained by the reciprocal crosses between S41 and S42 showed a better growth in vitro than those of either of the inbred parents. Histological observations of the endosperm in vivo failed to reveal any developmental or cytological differences between the F1 endosperm and the endosperms of the parental strains.
3. Among the callus tissues obtained, only those from the strain S42 and S41×S42 have been cultured successfully for three years, while other cultures ceased to grow within a few months.
4. Progeny tests of the S41×S42 hybrid suggested that the two strains could be different in two or more genetic factors concerning the callus formation in the endosperm explant, although the phenotypic expression is influenced by environmental and nutritional factors. Furthermore, the genetic study of the waxy strain S43 suggested that it possesses a genetic factor for inhibiting callus formation.
5. None of indole-3-acetic acid, kinetin, and crude extracts of established tissue cultures gave a growth promoting effect on excised endosperm tissues, whereas the amino acid components of yeast extract were found to be essential for the callus formation in the explants.View full abstractDownload PDF (1104K) -
ETSUJI SUGAI, CHISATO HIRANO1965 Volume 40 Issue 5-6 Pages 357-363
Published: 1965
Released on J-STAGE: May 21, 2007
JOURNAL FREE ACCESSThis report dealt with the effectiveness of apholate, one of alkylating agents, in sterilising the male of the silkworm, Bombyx mori L., with special consideration on cytological consequences after treatment. When the male larvae were administered at the 1st day of the fifth instar with doses more than 300μg per insect they were almost completely sterilized, while no remarkable sterility was shown in the case of the treatment at the middle of the same instar with the same doses of the chemical. From the cytological observations, it has been elucidated that the necrotic cell death of spermatogonia has occurred first after treatment and spermatocytes at the time of treatment transformed into functionless abnormal spermatozoa whereas both spermatids and spermatozoa were highly resistant. From these results, the occurrance of male sterility caused by apholate is interpreted as being due to the transformation of treated spermatocytes into functionless spermatozoa and death of spermatogonia by which the succession of spermatogenesis is halted.View full abstractDownload PDF (1998K) -
YOSHINORI KURITA, TOSIHIDE H. YOSIDA, KAZUO MORIWAKI1965 Volume 40 Issue 5-6 Pages 365-376
Published: 1965
Released on J-STAGE: May 21, 2007
JOURNAL FREE ACCESS1. Chromosome aberrations induced by a radiomimetic chemical, 4-nitroquinoline 1-oxide, in Yoshida sarcoma cells were of chromatid type.
2. The distribution of chromatid intrachanges (breakages) among cells was nonrandom. Frequency of intrachanges in each chromosome group was not proportional to the length of metaphase chromosomes.
3. The distribution of chromatid interchanges (translocations) among cells was also nonrandom.
4. Frequencies of both intra- and interchanges increased proportionally to the dose 8hr. after treatment. However, the frequency of interchanges observed 24hr. after treatment showed no proportional to the dose.
5. The aberrations were largely localized in the neighbourhood of the secondary constrictions. Possible interpretations for their origin as well as for their location in those regions were presented.View full abstractDownload PDF (1277K) -
YUKINORI HIROTA1965 Volume 40 Issue 5-6 Pages 377-385
Published: 1965
Released on J-STAGE: May 21, 2007
JOURNAL FREE ACCESS1.F elimination: acridine dyes convert F+ male or F'+ male clones of E. coli into stable F- female forms. The main factors which affect the rate of conversion of F+ or F'+ are the concentration of acridinium ions in the treating medium and the growth of the treated cells in the presence of the dye. Furthermore, the accessibility of F factor to acridine treatment depends upon the state of F factor in the host cell. Acridine orange increases the frequency of conversion from F+ to F- directly without appreciable selective growth. The conversion from F+ or F'+ to F- is irreversible, as expected for the loss of a genetic particle. Hfr males are resistant to the disinfecting action of acridine dyes. These results are well accounted for by the dual nature of F factor, chromosomal F, and plasmid F.View full abstractDownload PDF (935K)
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