| Project/Area Number |
10660007
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Breeding science
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| Research Institution | KYOTO UNIVERSITY |
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Principal Investigator |
OKUMOTO Yutaka Kyoto University, Graduate School of Agriculture, Associate Professor, 農学研究科, 助教授 (90152438)
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| Co-Investigator(Kenkyū-buntansha) |
INOUE Hiromo Kyoto University, Graduate School of Agriculture, Instructor, 農学研究科, 助手 (40260616)
NAKAZAKI Tetsuya Kyoto University, Graduate School of Agriculture, Instructor, 農学研究科, 助手 (60217693)
TANISAKA Takatoshi Kyoto University, Graduate School of Agriculture, Professor, 農学研究科, 教授 (80026591)
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| Project Period (FY) |
1998 – 2000
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| Project Status |
Completed (Fiscal Year 2000)
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| Budget Amount *help |
¥3,400,000 (Direct Cost: ¥3,400,000)
Fiscal Year 2000: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1999: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1998: ¥1,900,000 (Direct Cost: ¥1,900,000)
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| Keywords | rice / cold tolerance at booting stage / gene analysis / near-isogenic line / 穂ばらみ期耐冷性 / 穂ばらみ期 |
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| Research Abstract |
Exploitation of new genes for cold tolerance at booting stage of rice (Hereafter these genes are called tolerance genes for simplicity) was intended. To identify new tolerance genes, gene analyses for cold tolerance and development of new tester lines for cold tolerance were carried. Segregation analysis using F3 and F4 lines derived from the cross between EG3 (susceptible line) and EG5 (Aikoku : tolerant line) revealed that EG5 carried two complementary dominant genes for tolerance. Results from crosses of EG3/Aikoku3 (tolerant variety) and EG3/CTH5 (introduced tolerance from Hayakogane) suggested that both tolerant parents carried at least two tolerance genes. Comparing F3 lines derived from the cross combinations of EG3/Rikuu20 and EG3/Shinriki, most of the F3 plants were tolerant in the former combination while most of them were susceptible in the latter combination. This indicated that tolerance gene of Aikoku origin was dominant and that of Shinriki origin was recessive. Also, function of tolerance gene was investigated using CTH5 and near isogenic lines of Kirara397 for tolerence gene of Silewah (highly tolerant variety). Plants were put into the cold bath one month before the heading time (cold treatment) and effect of cold water on anther length, pollen fertility and seed fertility were observed. Irrespective of genotype for tolerance, all lines were severally reduced in anther length. Furthermore, anthers of plants grown under cold treatment become white and thin, while those of control plants were yellow and thick. For the relative anther length, lines with tolerance gene showed less reduction in it than the ones without tolerance gene. In pollen fertility, the former lines showed higher fertility than the later. Thus, it was suggested that effect of tolerance gene was expressed not only in pollen fertility but also in the growth of male reproductive organs.
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