頁籤選單縮合
題名 | 水稻臺中65號之早熟回交品系與早熟誘變品系所含早熟遺傳因子內部構造之比較研究 |
---|---|
作者 | 蔡國海; | 書刊名 | 中華農學會報 |
卷期 | 84 1973.12[民62.12] |
頁次 | 頁23-47 |
關鍵詞 | 內部構造; 水稻; 回交品系; 早熟; 臺中65號; 誘變品系; 遺傳因子; |
語文 | 中文(Chinese) |
中文摘要 | ?稻臺中65號為輪迴親本,應用連續回交法7次。育成其早熟品系A37與B967,前者攜帶原含於華北早熟?稻大同在來之早熟遺傳因子Ea,後者攜帶原含於日本早熟稻坊主5號之早熟遺傳因子Eb。臺中65號種子經放射線誘變之早熟品系I123 (r線)具有新誘發之早熟遺傳因子Eir,I190 (X線)具有新誘發之早熟遺傳因子Eix。此4種早熟遺傳因子E均較臺中65號早熟約10日,佔有同一因子座位。早熟回交品系與早熟誘變品系均隨增加與臺中65號回交次數,而延遲抽穗並增加植物體高度,暗示此等E遺傳因子座位為一複合座位,依交換可除去其部份遺傳因子而減弱其作用。回交過程中選拔固定較臺中65號早熟2~3日之品系,並經品系互相間雜交結果發現早熟遺傳因子座位內具有伴隨位置效果之偽似相對遺傳因子Ea(1), Eb(2), Eb(3) 以及 Eb(4)等之存在。其交換價為Ea(1)-Eb(3)為1.07%,Eb(2)-Eb(3)為0.31%,Eb(2)-Eix(4)為0.92%, Eb(3) -Eix為0.56%,而兩個遺傳因子在Cis排列時始表現E遺傳因子之作用。本研究E遺傳因子座位係由此等小遺傳因子合成,經交換而不同於排列終於形成同位相對遺傳因子系。 本研究所用7?稻品種及兩誘變品系皆共有早熟遺傳因子E,而屬於第8連鎖?與向地性遺傳因子la具有38%交換價單位。 |
英文摘要 | A variety of the Ponlai or Taiwan-Japonica rice (Oryza sativa L.), Taichung 65 (abridges as T65) was exclusively used as the recurrent pareent of backcrosses. As the donor parents (used as pollen parents), two early maturing Japonica varities, Tatung-tsailai from northern China (about 35 days earliner than T65) and Bozu 5 from northern Japan (about 25 days earlier heading than T65) were used. In each backcross generation, a few heterozygotes showing a certain degree of earliness as compared with T65 were selected for further crossing. Homozygous lines with an earliness gene were released by selfing the F1 plants of B7, B10, B13, B15 and B20 generation. The backcross progenies with genes from Tatung-tsailai are denoted by A and thoses genes from Bozu 5 by B. Further, the seeds of T65 were irradiated with gamma-rays (25 Kr) and X-rays (40 Kr), respectively. From the M3 generation, early-maturing lines giving a relatively high yield, I123 (gamma-rayed) and I190 (X-rayed) were selected. They are 10 to 11 days earlier heading than T65 and carry mutant genes Ei(r) and Ei(x), respectively. They were backcrossed to T65 twice to five times to produce isogenic lines, I1232, I1235, I1903 and I1905. The early-maturing isogenic lines, A37 and B967, were crossed with T65 and also with each other. The hybrids from the crosses of T65×A37 and T65×B967 had the same heading date as of earlier parental lines, and the F2s segregated into 3 early: 1 late (T65 type) plants. The F2 between A37 and B967 showed essentialy the same pattern of distribution of heading dates as of the parental lines. Therefore, it has been asserted that the two lines each has an earliness gene, Ea in A37 and Eb in B967, and the two genes are at the same locus. The recessive allele in T65 is symbiled by e. The early-maturing mutant I123 and I190 were also crossed with T65, A37 and B967. When crossed with T65, earliness was dominant in the F1 hybrids and the F2 gave a 3 early: 1 late ratio. When crossed with A37 or B967, the F1 hybrids showed the same heading date as of the parents and the F2 plants were distributed within the range of the parents. This indicated that the induced earliness genes, Ei(r) in I123 and Ei(x) in I190, are dominant and have the same locus as of Ea and Eb. The isogenic lines under observation must carry a chromosome segment from the donor parent in which an earliness gene is located. According to Hanson's (1959) expectation, the length of the segment would be about 1/n of the chromosome arm, letting n stands for the number of backcross generations. A37 shows slightly earlier heading date than B967. To account for the genetic basis of this difference, the heading dates of isogenic lines purified by different numbers of additional backcrosses to T65 were compared with one another in repeated experiments shown on different dates. The results showed that A310 was significantly later-heading than A37 but was still earlier heading than B9610. B9610 was also later-heading that B967 though the difference from B967 did not reach 5% level of significance. Such a mitigating effect of additional backcrossing, though statistically insignificant, could be seen until B13 or B15. It was also found that A310, A313, A315 and A320 were slightly but significantly taller than A37. No such difference in plant height was found in the B-line-group. The mutant lind backcrossed twice or five times to T65, I1232 and I1235, were significantly later heading and taller than the original mutant line I123; and I1903, I1905 were also later heading and taller than I190. These were found to be due to elimination of certian induced genes closely linked with Ei. It is difficult to detect a small difference (say, one day) in mean heading date between two given lines. Within the limitation of preciseness of out experiments, it could be concluded that I190> A37≒I123>A310≒A313≒A320≒B967≒B9610≒B9620≒I1232≒I1235≒I1903>I1905 in the order of earliness. Thus, the Ea, Eb, Ei(r) and Ei(x) genes having the same locus slightly differ in the intensity of effect. They may be considered to be isoalleles as difined by Stern and Schaeffer (1943). Another evidence indicative of the structure of the E locus was obtained from the crosses of A37l×B9615l, B967l×B9615l, B967l×I1905l, and B9615l ×I1905l, each parental heading slightly earlier than T65. The F2 populations between T65 and these lines showed no significant segregation. Those of A37×A37l, B967×B967l, B9615×B9615l, and I1905×I1905l, each gave a 3 early: 1 late (T65 type) ratio. A37l× B9615l produced F1 plants of the parental type, and 283 of 286 F2 plants observed also showed almost the same heading dates as of T65. But the rest three F2 plants were as early heading as if they had an E gene. In the same way, B967l×B9617l produced one early type of 339 F2 plants observed, B967l×I1905l produced three early type of 337 F2 plants, and B9615l×I1905l also produced one early type of 250 F2 plants.. These experimental results suggest that A37l, B967l, B9615l and I1905l each has a different fraction of the E gene-block (Ea(1), Eb(2), Eb(3) and Eix(4), respdctively, and when the two fractions are put together in "cis", they work similarly as E gene: but they are ineffective in the F1s of these crosses in which they were in "trans". The crossover value between Ea(1) and Eb(3) was estimated to be 1.1%, Eb(2) and Eb(3) was to be 0.3%, Eb(2) and Eix(4) was to be 0.9%, and Eb(3) and Eix(4) was to be 0.6%. It may be concluded from above-mentioned that the E locus comprises various gene sites. The E locus was in the 8th linkage group and distributed in seven early varieties of the Japonica type, and two early mutants, were all examined in this studies. |
本系統之摘要資訊系依該期刊論文摘要之資訊為主。