State Key Laboratory of Genetic Engineering, Institute of Genetics, School of Life Sciences, Fudan University, Shanghai 200433, China.
J Integr Plant Biol. 2011 Apr;53(4):312-23. doi: 10.1111/j.1744-7909.2011.01031.x. Epub 2011 Mar 21.
A dwarf mutant, designated LB4D, was obtained among the progeny of backcrosses to a wild rice introgression line. Genetic analysis of LB4D indicated that the dwarf phenotype was controlled by a single semidominant dwarfing gene, which was named LB4D. The mutants were categorized as dn-type dwarf mutants according to the pattern of internode reduction. In addition, gibberellin (GA) response tests showed that LB4D plants were neither deficient nor insensitive to GA. This study found that tiller formation by LB4D plants was decreased by 40% compared with the wild type, in contrast to other dominant dwarf mutants that have been identified, indicating that a different dwarfing mechanism might be involved in the LB4D dominant mutant. The reduction of plant height in F(1) plants ranged from 27.9% to 38.1% in different genetic backgrounds, showing that LB4D exerted a stronger dominant dwarfing effect. Using large F(2) and F(3) populations derived from a cross between heterozygous LB4D and the japonica cultivar Nipponbare, the LB4D gene was localized to a 46 kb region between the markers Indel 4 and Indel G on the short arm of chromosome 11, and four predicted genes were identified as candidates in the target region.
一个矮秆突变体 LB4D 是在回交后代中得到的，其亲本之一是一个野生稻渐渗系。LB4D 的遗传分析表明，该矮秆表型由一个单隐性矮秆基因控制，该基因被命名为 LB4D。根据节间缩短的模式，突变体被归类为 dn 型矮秆突变体。此外，赤霉素（GA）反应测试表明，LB4D 植株对 GA 既不缺乏也不敏感。本研究发现，与已鉴定的其他显性矮秆突变体相比，LB4D 植株的分蘖形成减少了 40%，表明可能涉及不同的矮秆机制。在不同的遗传背景下，F1 植株的株高降低幅度从 27.9%到 38.1%不等，表明 LB4D 表现出更强的显性矮秆效应。利用 LB4D 杂合体与粳稻品种 Nipponbare 杂交产生的大 F2 和 F3 群体，将 LB4D 基因定位到 11 号染色体短臂上标记 Indel 4 和 Indel G 之间的 46kb 区域，在目标区域中鉴定出四个预测基因作为候选基因。
