| Project/Area Number |
17580012
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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 | National Institute of Agrobiological Sciences |
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Principal Investigator |
HANDA Hirokazu National Institute of Agrobiological Sciences, Plant Genome Research Unit, Senior Researcher, 基盤研究領域・植物ゲノム研究ユニット, 主任研究員 (20343957)
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| Project Period (FY) |
2005 – 2006
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| Project Status |
Completed (Fiscal Year 2006)
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| Budget Amount *help |
¥3,100,000 (Direct Cost: ¥3,100,000)
Fiscal Year 2006: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 2005: ¥2,000,000 (Direct Cost: ¥2,000,000)
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| Keywords | Mitochondria / Rapeseed / Cytoplasmic inheritance / Plasmid / Paternal transmission |
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| Research Abstract |
In many higher plants, mitochondria are transmitted uniparentally from the maternal plant to progeny, and the main genomic DNAs and smaller DNAs in mitochondria are also transmitted from the maternal plant to progeny along with the transmission of mitochondria. However, rapeseed mitochondrial plasmid can be transmitted to progeny plants through at a very high rate.
In order to explore the origin of plasmid molecule and to elucidate the effect of nuclear or cytoplasmic background for the transmission and maintenance of plasmid, the presence of mitochondrial plasmid and type of mitochondrial genome were investigated using 78 Japanese rapeseed varieties and landraces, and a comparative analysis was carried out along with the breeding lineage of modern rapeseed varieties in Japan.
The mitochondrial genome of rapeseed was classified roughly into two types, type I (nap) and type II (cam). Type II of rapeseed mitochondria closely resembles that of B.rapa, which is related-species of rapeseed. In this study, the author found that all of varieties with type II mitochondria are originated from interspecific crosses between rapeseed (B.napus) and B.rapa. This indicates that type II cytoplasm was introduced to rapeseed by the process of a breeding program. The presence of plasmid was limited to B.rapa landraces and rapeseed varieties that arose by interspecific crosses between B.napus and B.rapa. The results suggest that mitochondrial plasmid is of B.rapa origin and that it has been introduced into rapeseed by interspecific crosses in a modern breeding program as in the case of the mitochondrial genome. Phylogenetic study of Japanese rapeseed varieties suggests the participation of not the mitochondrial genome but nuclear genome for the perpetuation of plasmid in progeny varieties.
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