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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 6
Displaying 1-5 of 5 articles from this issue
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TOYOYUKI NISHI, SACHIHIKO MITSUOKA1969 Volume 44 Issue 6 Pages 341-346
Published: 1969
Released on J-STAGE: May 21, 2007
JOURNAL FREE ACCESSSuccessful production of haploid, triploid and pentaploid as well as diploid was achieved in the plants restored from anther callus and tetraploid from ovary callus, although only diploid plants were restored from embryo and shoot nodule callus. A series of plants in polyploid, x, 2x, 3x, 4x, and 5x, showed the ploidy-specific properties in morphological characteristic points.View full abstractDownload PDF (1787K) -
II. TRANSMISSION THROUGH MALE PARENTSSUMIO MINAMORI1969 Volume 44 Issue 6 Pages 347-354
Published: 1969
Released on J-STAGE: May 21, 2007
JOURNAL FREE ACCESSEvidences for paternal transmission of delta in D. melanogaster were presented. The Cy/S-5 daughters derived from the mating, Cy/S-5_??_×Cy/Pm_??_, did not show any symptoms for retention of delta (Minamori 1969). However, females of later generations of the Cy/S-5 line derived from the above mating produced a characteristic segregation distortion which indicates the presence of delta. The distortion became larger with later generations and reached a definite level which was expressed by females of the original Cy/S-5 strain. These findings indicate that delta may be transmitted through male flies, although the amount transmitted may be minute, and it may be gradually accumulated in the above line extending over many generations. The accumulation of delta appeared to be delayed in the lines derived from Cy/S-5 males of later generations after repeated backcrossing of the male to Cy/Pm females.
It was recognized that a total of 224 males sampled from the original Cy/S-5 strain and of 208 Cy/S-5 males sampled from the thirty-first generation of backcrossing had transmitted delta to their offspring, and no delta-free lines were obtained. Based on these facts, the nature of delta was discussed.View full abstractDownload PDF (779K) -
SAYAKA NAKAI, EIKO YAMAGUCHI1969 Volume 44 Issue 6 Pages 355-365
Published: 1969
Released on J-STAGE: May 21, 2007
JOURNAL FREE ACCESSExperiment has been carried out using UV-sensitive mutant of uvs 1 of Saccharomyces cerevisiae, presumably lacking ability of dark repair, to investigate genetic nature of UV-induced premutational damages leading to three-different types of mutation under the dark and illuminated conditions. Yields of these types of mutation in uvs 1 are markedly higher than those in wild type at equal doses. At the dark condition, logarithmically plotted dose-response curves of true-back mutations from arg 4-17, his 5-2 and lys 1-1 induced in uvs 1 consist of two straight lines. Slopes of the curves at high doses are more steeper than those at low doses and almost the same as those in wild type in all the dose range. The curves for induced frequency of super-suppressor mutation and that of back mutation from his 1-1, i.e., addition-deletion type mutation consists of one component, and their slopes are nearly equal for both uvs 1 and wild-type strains. Furthermore, ratios of true back mutation yields between uvs 1 and wild-type strains at equal doses are greater than those of super-suppressor mutations or reversion of addition-deletion type. To account for these results it is postulated that premutational damage leading to true-back mutation is preferentially repairable compared with damages responsible for the other types of mutation. Molecular natures of the premutational damages leading to the three types of mutation are discussed.View full abstractDownload PDF (1082K) -
K. B. SINGH, D. SHARMA, P. D. MEHNDIRATTA1969 Volume 44 Issue 6 Pages 367-377
Published: 1969
Released on J-STAGE: May 21, 2007
JOURNAL FREE ACCESSA set of seven wheat varieties from two different ecogeographical origins were studied in a diallel cross to find out the combining ability and the genetic parameters for yield and its components. The general and specific combining ability estimates for spike number per plant, spikelets per spike and seed size indicated predominance of additive gene effects, while for yield the variance for general and specific combining ability were of same order, suggesting importance of additive as well as non-additive effects. Per se performance of the varieties was in close agreement with the general combining ability estimate.
The Vr-Wr and Wr-W' graphs showed overdominance for spikes per plant, spikelets per spike, 100-kernel weight and grain yield. In general the predictions regarding the parents made from general and specific combining abilities are in line with gene action indicated by the Vr-Wr and Wr-W' graphs for different characters.
Implications of the genetic parameters on breeding approach in wheat have been discussed.View full abstractDownload PDF (1035K) -
YASUSHI TAKENOUCHI1969 Volume 44 Issue 6 Pages 379-380
Published: 1969
Released on J-STAGE: May 21, 2007
JOURNAL FREE ACCESSDownload PDF (451K)
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