頁籤選單縮合
題 名 | 稉秈稻雜種後代稔實率及若干農藝性狀個體選拔效果之研究=Studies on the Effects of Individual Selection for Fertility and Some Agronomic Characters in the Progenies of Rice Hybrids between Indica and Japonica Types |
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作 者 | 盧守耕; 孔德諟; | 書刊名 | 中華農學會報 |
卷 期 | 42 民52.06 |
頁 次 | 頁1-12 |
關鍵詞 | 稉秈稻雜種後代; 稔實率; 農藝個狀; |
語 文 | 中文(Chinese) |
英文摘要 | Inter-subspecific hybrid progenies of rice often show partial sterility in early generations. This gives some troubles and confusions to the rice breeders when Indica × Japonica hybridization is used as the breeding program. In present studies, the effects of individual selection for fertility in early generations were studied. On the other hand, the effects of individual selection in early generations for four agronomic characters, viz. plant height, number of panicle per plant, length of panicle and number of grains per panicle, which are highly associated with the yields, were also studied. If the individual selection for these four characters in early generations were effective, it would be of significance to the rice breeders. Two rice crosses, Colusa (Japonica type) × Sheng-li-hsien (Indica type) and Taichung 65 (Japonica type) × Dan-kwan-hwa-loo (Indica), were made in 1956. From their F2 to F4 generation, individual selection on the bases of higher fertility (higher than 70%) and lower fertility (lower than 40%) were carried out on both directions in both crosses, while the selection for other four characters were also practiced. The effectiveness of individual selection was indicated by the simple correlation between generations. Results obtained could be summarized as follows: 1. Despite of what direction of the selection for fertility was made, the average fertility of next generation after selection was tending to the higher fertility. The continous selection toward lower fertility could not made lines fixed in low fertility or shifted in lower direction, but attaining to higher fertility in later generations. The only difference in consequence of this two directions selection is that the average fertility of the lines deriving from the selections of high fertility (above 70%) in the former generation was higher than that of the lines deriving from the lower fertile selections (lower than 40%). The differences between the average fertilities of these two selected populations were highly significant in the generations F8~F5, and ranged from 10~20% only. It is therefore, concluded that the partial sterility of intersubspecific hybrid progenies in rice is not purely controlled by genes. 2. The parent-offspring corraltion for fertility between F2 individuals and their progeny lines in F3, F4 or F5 showed insignificant in both crosses, but that of F3~F4 and F4~F5 were highly significant (Table 3). It seems that there is not effect to select for fertility before F3 generation. 3. The correlations of plant height between generations are given in Table 6 and 7. They are all highly significant, indicating that the individual selection for plant height even in F2 early generation is of efficiency. 4. The correlations of number of panicle per plant and panicle length between F2 individuals and the lines of all later generations were all insignificant, while that between F3 individuals and lines of F4 and F5 were significant. (Table 6 and 7). It is obvious that selection before F3 for these two characters is of no effect. 5. The parent-offspring correlation of the number of grains per panicle between all generations were insignificant except that of F4~F5. Thus the selection for this character in early generations would be not effective until F4. 6. The heritabilities of above-mentioned four characters were estimated by the method of F3~F2 regression. The heritability of plant height is highest among these four characters, that of number of panicle and panicle length are second, and that of number of grains per panicle is lowest (Table 8). |
本系統中英文摘要資訊取自各篇刊載內容。