Inheritance of Cytoplasmic Male Sterility and Restorer Fertility Gene in a Developed Rice Line, RT98C
| Autor: | Motomura, Keiji, Ishimine, Yukio, Murayama, Seiichi, Higa, Teruo, Goya, Akira, Tomoyose, Tetsuo |
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| Jazyk: | japonština |
| Rok vydání: | 2001 |
| Předmět: | |
| Zdroj: | 熱帯農業 = Japanese Journal of Tropical Agriculture. 45(3):202-208 |
| ISSN: | 0021-5260 |
| Popis: | Oryza rufipogonの1系統K98を一回母本に栽培イネの台中65号で8回の連続戻し交雑をし, その後自殖をくり返して核置換系統RT98Cを育成した.同育成系統は正常な花粉および種子稔性をもつが, 台中65号との交雑後代においては不稔個体を生ずる場合があった.そこで稔性に関する遺伝実験を行った結果, 次の結論を導くことができた.稔性は細胞質と核内の1座性の稔性回復遺伝子(Rf-rf)により支配されており, また配偶体支配型であった.ただし, 雌性配偶子は細胞質や稔性回復遺伝子の種類に関わらず常に正常稔性を示しており, 稔性支配を受けるのは雄性配偶子のみであった.すなわち, RT98Cの細胞質は雄性不稔細胞質(msc)であり, この中ではRf遺伝子をもつ花粉は正常に発育するが, rf遺伝子をもつ花粉は退化して受精機能をもたなかった.一方, 台中65号の細胞質は正常な細胞質(mfc)であり, この中ではRfをもつ花粉もrfをもつ花粉も正常に発育した.ヘテロ個体(msc)Rfrf個体を自殖させた場合, 全て種子稔個体となり種子不稔個体が全く現れなかったことから, 稔性は配偶体支配型であることが認められた.なお, ヨード・ヨードカリ液での花粉の染色具合, あるいは花粉の大きさなどは接合体の遺伝子型に関係なく正常花粉も退化花粉もほぼ同様であり, 区別できなかった. Through successive backcrosses, the cytoplasm and nuclear fertility restorer gene of K98,a line of Oryza rufipogon, were introduced into Taichung 65,O. sativa, and a nuclear-substituted line, RT98C, was developed. This line showed a high degree of spikelet fertility, but it produced fertile and sterile plants in the cross with Taichung 65. To analyze the mode of inheritance of the fertility, crossing tests were carried out, and the following results were obtained. Pollen fertility was controlled by the interaction of the cytoplasm and the single restorer fertility gene (Rf-rf), but the function of the embryosac was not affected by the cytoplasm and restorer fertility gene. That is, all the pollen grains in the cytoplasm of Taichung 65 were normal regardless of the dominance or recessiveness of the restorer fertility gene they carried. On the other hand, the pollen grains carrying the Rf gene in the cytoplasm of RT98C were normal, while the pollen grains carrying the rf gene in this cytoplasm became sterile. The normal cytoplasm of Taichung 65 was designated as (mfc) and the sterile cytoplasm of RT98C as (msc). When the (msc) Rfrf plants were selfed, in all the resulting plants, spikelet fertility was restored, and no sterile plants were observed, suggesting that the pollen grains carrying the rf gene were not viable. Thus, the male sterility and fertility restoration in this line were controlled by the genotype of the gamete itself but not by that of the zygote, indicating the presence of a gametophytic control of fertility. Only in the (msc) rfrf plants spikelet fertility was not restored, while in the plants with all the other genotypes, viz. (msc) RfRf, (msc) Rfrf, (mfc) RfRf, (mfc) Rfrf and (mfc) rfrf, spikelet fertility was restored, resulting in a high degree of spikelet fertility. Although pollen grains carrying rf in (msc) degenerated regardless of the plant genotype (Rfrf or rfrf), they all stained well in a I_2KI solution and showed a normal size. 論文 |
| Databáze: | OpenAIRE |
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