2005 Fiscal Year Final Research Report Summary
Eco-physiological analysis on hybrid rice productivity using genome information
| Project/Area Number |
15380013
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (B)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Crop science/Weed science
|
|---|
| Research Institution | The University of Tokyo |
|---|
Principal Investigator |
NEMOTO Keisuke The University of Tokyo, Graduate school of Agricultural and Life Sciences, Professor, 大学院農学生命科学研究科, 教授 (40211461)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
YAMAGISHI Junko The University of Tokyo, Graduate school of Agricultural and Life Sciences, Associate Professor, 大学院農学生命科学研究科, 助教授 (60191219)
YAMAGISHI Toru The University of Tokyo, Graduate school of Agricultural and Life Sciences, Associate Professor, 大学院農学生命科学研究科, 助教授 (50143409)
GOTO Yusuke Tohoku University, Graduate school of Agricultural Science, Associate Professor, 大学院農学研究科, 助教授 (80122919)
|
|---|
| Project Period (FY) |
2003 – 2005
|
| Keywords | rice / quantitative traits / heterosis / epistasis |
|---|
| Research Abstract |
Rice (Oryza sativa L.) includes two subspecies, namely ssp. japonica and ssp.indica. Although japonica-indica intersubspecific cross has been very rarely used in the past rice breeding programs, rice breeders have been aware that hybrid plants between japonica x indica cross frequently exhibit notable heterosis in many agronomic traits such as biomass production, stress tolerances, etc. This project was aimed to clarify how these characters are controlled genetically in segregating populations from japonica x indica crosses that show high heterosis. For this purpose, we carried out quantitative trait locus (QTL) analyses using Nekken 2 (lowland japonica) x Gaya (lowland indica) recombinant inbred lines, Kamenoo (lowland japonica) x Dular (rainfed-lowland indica) recombinant inbred lines, and IR36 (lowland indica) x Genjah Wangkal (upland japonica) recombinant inbred lines which were originally developed in our laboratory. We found that gene to gene interactions (epistasis) are the major cause of transgressive segregation in many traits. We also found that linked small QTLs for some traits (eg. tiller bud dormancy and phyllochron) have a multiplicative large effect on their product (e.g. tiller number), suggesting that epistasis is, at least in part, integrated at morphological level.
|
