| Project/Area Number |
09660005
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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 | Nagoya University |
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Principal Investigator |
KITANO Hidemi Faculty of Agriculture Nagoya University Associate Professor, 農学部, 助教授 (50144184)
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| Project Period (FY) |
1997 – 1998
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| Project Status |
Completed (Fiscal Year 1998)
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| Budget Amount *help |
¥3,000,000 (Direct Cost: ¥3,000,000)
Fiscal Year 1998: ¥1,400,000 (Direct Cost: ¥1,400,000)
Fiscal Year 1997: ¥1,600,000 (Direct Cost: ¥1,600,000)
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| Keywords | rice / embryogenesis / endosperm / mutation / giant embryo / seed / 粒大 |
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| Research Abstract |
The author examined embryo-endosperm interaction in developing rice seeds using the different recessive mutants control the embryo size. The mutants named as giant embryo (ge) had a large-sized embryo and relatively small-sized endosperm compared with wild type seeds. On the contrary, reduced embryo (re) mutants had a small-sized embryo (relatively large-sized endosperm). Furthermore, the mutants, embryolessl (emll) aborted embryo development in early stages or contained a tiny and globular organless embryo in the matured seed. However, emll mutants were available infrequently to produce wild type embryos responded to the low temperature conditions during seed development.
Genetic analysis between the mutants showed the epistasis, i.e. emll >re >ge. Double mutants segregated from F_2 of the crosses between ge and some other embryospecific mutants, globular embryo (gle) or club-shaped embryo (cle) had a gle- or cle - type embryo and simultaneously a large cavity around their embryos. Such phenotypes observed in the double mutants demonstrated that ge could be control not directly but indirectly the embryo size through the regulation of endosperm development.
Histological observations. of the mutants during embryo and endosperm developments revealed that these mutant genes control not cell divisions but an accumulation of storage substances such as starch grains in the endosperm cells around the embryo.
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