水稻茎叶形态性状的简化三重测交分析

以H1459和乐一为测验系L_1和L_2,分别与泸红早等22个早籼品种进行简化三重测交(sTTC),考查了12个茎叶形态性状。其中,剑叶宽、倒2叶宽、倒3叶宽,倒2节间长和基部节间粗在两个测验系中表现为极端类型,倒3叶长和剑叶夹角在两个测验系间可能存在由于同效基因分散分布引起的真实遗传差异。对上述7个性状的遗传分析表明,基部节间粗

Simplified Triple Test Cross Analysis of Some Stem and Leaf Morphological Characters in Rice (Oryza sativa L.)

Two rice varieties, H1459 and Le-Yi (L_1 and L_2) were used as testers to crosswith 22 early season indicas in a simplified triple test cross (sTTC) analysis. It wasfound that, when compared to the lines being tested, the two testers showed extremephenotypic values in 5 of the 12 characters examined, including width of the1st (flag), 2nd, and 3rd leaf, 2nd internode length (SIL) and basal internode thick-ness (BIT). True genetic difference were found to exist between the two testers forthe other two characters, i.e., 3rd leaf length and the angle between the 1st leaf andthe stem, caused possibly by the dispersal of genes with similar effect. Further geneticstudies were devoted, therefore, to only these 7 characters. Studies on gene effect revealed that the genetic variation of BIT was determinedonly by additive gene effect, but those of the other characters were influenced not onlyby additive (or dominant) effect, but also by epistatic effect. No dominant effect wasdetected for the 1st and 2nd leaf width and BIT, but partil dominance did exist forthe other characters. Dominance was usually unidirectional for SIL, butamphidirectional for 3rd leaf length. Estimates of heritabilities were high for 3rd leaflength, 1st and 2nd leaf width, low for 1st leaf angle and BIT, and intermediate forthe other characters. Predition of the limits of segregation indicated that using L_1 andL_2 as parents, it is possible to obtain lines with 3rd length and 1st leaf angle superiorto both parents as a result of recombination. Some problems concerning sTTC analy-sis were also discussed.