| Project/Area Number |
12460006
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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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 | Fukui Prefectural University |
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Principal Investigator |
MURAI Kouji Fuki Prefectural Department of Bioscience, Associate Professor, 生物資源学部, 助教授 (70261097)
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| Project Period (FY) |
2000 – 2002
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| Project Status |
Completed (Fiscal Year 2002)
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| Budget Amount *help |
¥8,800,000 (Direct Cost: ¥8,800,000)
Fiscal Year 2002: ¥1,600,000 (Direct Cost: ¥1,600,000)
Fiscal Year 2001: ¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 2000: ¥6,000,000 (Direct Cost: ¥6,000,000)
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| Keywords | wheat / cytoplasmic male sterility / pistillody / mitochondrial DNA / fertility-restoring gene / MADS box gene / nuclear-cytoplasm interaction / alloplasmic line |
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| Research Abstract |
The alloplasrmic line of wheat cv. Norin 26 (N26) with the cytoplasm of a wild relative species Aegilops crass shows pistillody, homoerotic transformation of stamens into pistil-like structures, when grown under long-day conditions (>15 h light). This phenomenon was named photoperiod-sensitive cytoplasmic male sterility (PCMS) and studies to develop a new hybrid wheat production system. Contrary to N26, wheat cv. Chinese Spring (CS) does not show the PCMS because of the presence of Rfd1 gene located on the long arm of chromosome 7B. The objective of this research project is to elucidate the molecular basis of the PCMS.
1. Pistillody in the lines
A loss-of function study of Rfd1 using ditelosomic 7BL alloplasmic line revealed that the Ae. Crassa cytoplasm essentially induces the pistillody independent of long photoperiod. The fertility restoration under the short-day conditions in the alloplasmic N26 could be controlled by gene(s) preventing the influence of the Ae. Crassa cytoplasm which functions under short photoperiod.
2. Wheat MADS box genes
Analyses of wheat MADS box genes revealed that the pistillody is caused by the deficiency of class B MADS box gene expression in the stamen primordia of the alloplasmic lines.
3. Mitochondrial genes associated with the pistillody
A subtraction study indicated that coxl gene and atpA chimeric gene are preferentially expressed in the pistillody line. This suggests that these mitochondrial gene products are associated with the induction of pistillody in the alloplasmic lines.
Hybrid wheat breeding using the PCMS
According to the results of present research, the problems to be solved for practical hybrid wheat breeding were clarified.
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