All issues
Successor
Volume 45 (1970)
- Issue 6 Pages 425-
- Issue 5 Pages 319-
- Issue 4 Pages 239-
- Issue 3 Pages 173-
- Issue 2 Pages 87-
- Issue 1 Pages 1-
Volume 45, Issue 3
Displaying 1-8 of 8 articles from this issue
- |<
- <
- 1
- >
- >|
-
NOBUMICHI INOMATA1970 Volume 45 Issue 3 Pages 173-182
Published: 1970
Released on J-STAGE: May 21, 2007
JOURNAL FREE ACCESSEmbryological studies were made to clarify developmental processes, leading to seed collapse in crosses between diploid Raphanus sativus (2n=18) and its autotetraploid (2n=36).
Hybrid embryos of reciprocal crosses appeared to develop normally in the early developmental stage, but in the cross, 2x×4x, they failed in general to develop beyond the globular stage because of degeneration of the endosperm. In the reciprocal cross, 4x×2x, viable hybrid seeds were produced, though their sizes were only one-fourth those of their parents.
In the 2x×4x cross, cell wall formation in the endosperm was inhibited, and abnormal vacuolization of endosperm occurred in all ovules, resulting in various nuclear irregularities and degeneration of ovules.
In the 4x×2x cross, the amount of endosperm was smaller but cell wall formation took place in it earlier than in parental endosperm. Development of the embryo was faster than in the parents.
A possible cause for the failure of viable seed formation was discussed in relation to the various abnormalities observed in various developmental stages.View full abstractDownload PDF (991K) -
YOSHIAKI YONEDA1970 Volume 45 Issue 3 Pages 183-188
Published: 1970
Released on J-STAGE: May 21, 2007
JOURNAL FREE ACCESSPeroxidase isozymes in four geographical strains of Pharbitis nil, TO16 (Japanese), Tendan (Chinese), Nepalese and African, were compared. Though they had similar zymograms, the Nepalese and African strains showed one and three bands in addition to those found in TO16, respectively. The African strain had a cathodal band, 2C, while the others had 1C. Genetic analysis showed that these two isozymes were controlled by alleles Pe1C and Pe2C, respectively. A Japanese strain seemed to have a null form for 1C controlled by an inactive allele, PeO at the same locus.View full abstractDownload PDF (952K) -
TOMOSABURO YABUNO1970 Volume 45 Issue 3 Pages 189-192
Published: 1970
Released on J-STAGE: May 21, 2007
JOURNAL FREE ACCESSWhen the panicles of four perennial and rhizomatous West African plants of E. pyramidalis were self-pollinated by bagging, they showed a very low seed fertility in spite of their high pollen fertility.
But, when two panicles of different plants were bagged together, the seed fertility was remarkably improved. Partial self-incompatibility was reported for the first time in the genus Echinochloa.View full abstractDownload PDF (583K) -
A. FUKATAMI, D. MORIWAKI1970 Volume 45 Issue 3 Pages 193-204
Published: 1970
Released on J-STAGE: May 21, 2007
JOURNAL FREE ACCESSThe aim of the present study was to produce sexual isolation between two mutant strains, brown and ebony, of D. melanogaster with or without X-ray treatment. These two mutant strains were prepared in such a way as to have a nearly common genetic background before selection.
A new selection procedure for the collection of the parents for the next generation, which is modified from that of Koopman, was applied. Four hundred flies in total, one hundred females and one hundred males of each of two mutant strains, were put into a population cage for 72 hours or into a population bell for 48 hours. Each female was isolated individually and allowed to lay eggs after the mating period and the type of mating was determined by the progeny test. On the average, about 20 percent of double matings were observed during 72 hours. In this study, progenies from homogamic matings were selected as the parents exclusively. The proportion of females producing wild type progeny was taken as the measure of the sexual isolation.
Regression coefficients of frequencies of females which produced wild type progeny in all four selected lines with X-ray treatment were negative, whereas three were positive in four selected lines without X-ray treatment. Selection for sexual isolation may be effective under the conditions of an effective procedure applied and with X-ray treatment producing gene mutations which affect mating preference.View full abstractDownload PDF (876K) -
SADAO ICHIKAWA1970 Volume 45 Issue 3 Pages 205-216
Published: 1970
Released on J-STAGE: May 21, 2007
JOURNAL FREE ACCESSInflorescences of Tradescantia reflexa (4x, 2n=24) KU 7 clone which is heterozygous for flower color (blue/pink, blue being dominant) were irradiated acutely with 37 to 141 rads of 14.1MeV fast neutrons and with 144 to 362rads of 137Cs gamma rays. The stamen hairs of the irradiated and control flowers were examined daily for 19 days after irradiation.
At the time when the maximum radiation effects were observed, 1) the average number of cells per hair, 2) percentage of stunted hairs, 3) postirradiation growth of hairs, 4) pink mutant events per hair, 5) percentage of pink mutant cells, and 6) colorless events per hair were calculated for each dose and the effects of fast neutrons and gamma rays were compared. The determined RBEs of 14.1MeV fast neutrons as compared with 137Cs gamma rays for the above six end points were 1) 3.95, 2) 3.50, 3) 3.41, 4) 5.05, 5) 4.82, and 6) 5.32, respectively. These RBE values are much lower than those usually obtained from higher plants (mostly dry seeds) and are closer to those from other organisms. This point is discussed with respect to water content and dose-rate effects.View full abstractDownload PDF (1102K) -
SADAO ICHIKAWA1970 Volume 45 Issue 3 Pages 217-224
Published: 1970
Released on J-STAGE: May 21, 2007
JOURNAL FREE ACCESSSeeds of Triticum boeoticum, a diploid wheat species, and of its autotetraploid were soaked for 14hrs at 20°C and were irradiated acutely with appropriate doses of 14.1 MeV fast neutrons or of 137Cs gamma rays. The effects of both the radiations were compared based on the data of seedling height measured 31 days after irradiation and of wet and dry weights of 49-day-old seedlings. The RBE values of 14.1MeV fast neutrons as compared with 137Cs gamma rays were determined to be 3.12, 3.48 and 3.52 for the reduction of seedling height, wet weight and dry weight, respectively, in the diploid, and 2.66, 2.80 and 2.74, respectively, in the autotetraploid. These values are evidently lower than those obtained earlier from dry seeds, and it is obvious that water content modifies RBE value.View full abstractDownload PDF (674K) -
YOSHIHISA FUJIO1970 Volume 45 Issue 3 Pages 225-232
Published: 1970
Released on J-STAGE: May 21, 2007
JOURNAL FREE ACCESSA study has been made to determine whether the blood group gene B controls the focus formation on chorioallantoic membrane as well as splenomegaly, and if it is a case, to determine on the effect of the gene B quantitatively.
It was found that the gene B controlled the focus formation as well as splenomegaly when the host embryos possessed the antigen controlled by the gene B. In the absence of B antigen, other antigens were responsible to produce foci without changes in spleen weight. It suggested that a second gene-C blood group gene-controlled the focus formation without splenomegaly when the host embryos possessed no antigen controlled by the gene B.
In BABA hosts, BbBb donor produced the largest focus number than did BBBB, BMBM, BGBG, and BKBK donors. Both BBBB and BMBM donors produced intermediate focus numbers. It is suggested that the differences in the competence of donor to produce focus may depend upon the differences in genotypes of the gene B in the donors.View full abstractDownload PDF (719K) -
ICHIRO SHIKATA, MASAO AIHARA, HIROSHI OKADA, TAKAAKI SHINOMIYA, MICHIH ...1970 Volume 45 Issue 3 Pages 233-236
Published: 1970
Released on J-STAGE: May 21, 2007
JOURNAL FREE ACCESSDownload PDF (212K)
- |<
- <
- 1
- >
- >|