1998 Fiscal Year Final Research Report Summary
ANALYSES OF DISTRIBUTION AND FUCTION OF HYBRID STERILITY GENE LOCI IN RICE GENOME
| Project/Area Number |
08456001
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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 | KYOTO UNIVERSITY |
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Principal Investigator |
IKEHASHI Hiroshi KYOTO UNIVERSITY,GRADUATE SCHOOL OF AGR.PROFESSOR, 農学研究科, 教授 (50193222)
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| Co-Investigator(Kenkyū-buntansha) |
NAKAZAKI Tetuya KYOTO UNIVERSITY,GRADUATE SCHOOL OF AGR.INSTRUCTOR, 農学研究科, 助手 (60217693)
OKUMOTO Yutaka KYOTO UNIVERSITY,GRADUATE SCHOOL OF AGR.LECTURER, 農学研究科, 講師 (90152438)
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| Project Period (FY) |
1996 – 1998
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| Keywords | Hybrid sterility / Genetic analyses / Oryza sativa / Hybrid rice breeding / Fixation of mutants |
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| Research Abstract |
Genetic analysis of hybrid sterility gene has been a major target of rice research for the last half a century because it may explain phylogenic differentiation of rice. Recently solution for the hybrid sterility has been required to obtain the enhanced hybrid vigor which is found in hybrid between different groups of rice.
Following the preceding identification of hybrid sterility gene loci of S5, S7, S8, S9, S15, S16 and S17 on several chromosomes, the precise positions for S7 and S17 were determined by RFLP.Further, new hybrid sterility gene loci were found on chromosome 3 and 11 using isozyme markers of Pgi-l and Pgd-l in the analysis of hybrid sterility gene of major cms lines. Hybrid sterility genes for male gametes were also analyzed on chromosome 7 and 3 using isozyme markers.
A newly mutated allele at a hybrid sterility gene locus S7 was found to be fixed without any phenotypic disturbance. Thus, a model for accumulation of mutated alleles at hybrid sterility loci was proposed, in which a change from S^n/SS^n to SS^n/SS^I may directly fix both genotypes of SS^n/SS^n and SS^i/SS^i.
This research is the first to show the distribution of hybrid sterility gene loci in rice and the possible cause of their accumulation in rice genome. An application of this research products to hybrid rice breeding was reported in a review by Science Vol. 283 (Page 313, Jan. 15, 999).
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