Ecological-Genetic Studies on Rice Germplasm in Tropical Asia (3rd Survey)
Grant-in-Aid for Overseas Scientific Survey.
|Research Institution||National Institute of Genetics|
OKINO Hiroko Nat. Inst. of Genet. Professor, 総合遺伝研究系, 教授 (70000247)
SONGKRAN Chi タイ国農業省, パトンタニ稲研究センター・遺伝資源, 主任
平岡 洋一郎 国立遺伝学研究所, 総合遺伝研究系, 助手 (20145113)
山岸 博 京都産業大学, 工学部, 助教授 (10210345)
佐藤 雅志 東北大学, 遺伝生態研究センター, 助手 (40134043)
島本 義也 北海道大学, 農学部, 教授 (00001438)
YAMAGISHI Hiroshi Kyoto Sangyo University Associate Professor
HIRAOKA Yo-Ichiro Nat. Inst. of Genet. Res. Associate
SHIMAMOTO Yoshiya Hokkaido University Professor
SATO Tadashi Inst. of Genetic Ecol. , Tohoku Univ. Res. Associate
SONGKRAN Chitrakorn Pathum Thani Rice Res. Center, Thailand Lab. Head
|Project Fiscal Year
1989 – 1990
Completed(Fiscal Year 1990)
|Budget Amount *help
¥6,000,000 (Direct Cost : ¥6,000,000)
Fiscal Year 1990 : ¥2,000,000 (Direct Cost : ¥2,000,000)
Fiscal Year 1989 : ¥4,000,000 (Direct Cost : ¥4,000,000)
|Keywords||Bhutan / Bangladesh / Thailand / wild rice / primitive rice cultivars / ecological-genetics / deepwater rice / permanent study-sites / 遺伝資源 / 野生イネ / 環境適応 / 浮稲 / 在来稲品種 / 生態遺伝学 / 高度勾配 / 自然集団の遺伝的構造|
We have carried out the variation survey of the common cultivated rice (Oryza sativa) and its wild progenitor (O. rufipogon) from the viewpoint of genetics and ecology. In 1989, we made study-tours in Bhutan and Bangladesh. In 1989 and 1990, we visited three times our permanent study sites of wild rice which are located in the Central Plains of Thailand.
1. Bhutan --- In West Bhutan we made observation of 22 rice fields distributed along three valleys and collected 158 seed samples. The field of the highest altitude we visited (probably the highest rice field in the world) was in 2700 m MSL. Rice fields were heterogeneous in varying degrees within population including variants which showed high seed shattering and semisterility. The origin of such "weedy" type remains unsolved. Character investigation of seed samples revealed that samples collected in higher altitude were mostly Japonica type, while those collected in lower altitudes were mostly Indica type.
2. Bangladesh --- Rice fields
in Bangladesh are distributed mostly in low-lying areas which are deeply flooded in the rainy season. We traveled three districts which are planted to deepwater rice and inhabited by wild rice. 66 cultivated and 30 wild rice samples were collected on 14 sites. Traditional methods of mix-cropping (mixture of two varieties having different growth duration) suggested an interesting problem of ecological genetics. Some of the accessions of cultivars were found to carry Japonica-specific isozyme alleles, although lowland cultivars in tropics have been believed as Indicas. In regards to wild rice, most of wild rice populations were found to be in close proximity to rice fields, and to be introgressed by genes of cultivated type. Fortunately, we found truly wild populations scattered forming small populations in a huge marsh places which were dominated by Datura.
3. Population study in Thailand --- Among eight permanent studysites which we are monitoring since 1983, four wild populations became extinct or nearly extinct. They are all annual type. The remaining four are perennial or intermediate perennial-annual type, and persist in relatively stable habitats. Thus, natural populations destruction or urbanization. Less
Research Output (11results)