一个水稻卷叶基因rl_(t)的精细定位

Fine Mapping of a Rolled Leaf Gene rl_(t) in Rice

叶片适度卷曲是水稻理想株型塑造的重要组成部分。卷叶基因rl(t)在杂合状态下可使叶片适度卷曲,增加水稻产量,具有较高的育种利用价值。以卷叶珍汕97B[携带rl(t)基因]与平展叶品种奇妙香(轮回亲本)杂交并回交的BC5F3和BC5F4为定位群体,在前人关于rl(t)的定位区间内设计了15对多态性分子标记,将rl(t)精细定位于第2染色体上分子标记P95053和P113.6之间的11kb范围内,遗传间距约0.04cM。区间内只包含1个释义基因,预测编码GL2类同源异型结构域,属于同源异型盒家族中的HD-GL2类(也称为HD-ZIPⅣ)转录因子。卷叶基因rl(t)的精细定位为克隆目标基因和研究其调控机理奠定了基础。

Moderately rolled leaf is one of the most important morphological characters in ideal plant architecture breeding in rice. The heterozygous rl（t） gene could produce moderately rolled leaf and increase rice yield, presenting a high breeding potential. By using BC5F3 and BC5 F4 populations derived from a rolled leaf Zhenshan 97B（carrying rl（t） gene） and a flat-leaf variety Qimiaoxiang（recurrent parent）, and a total of 15 polymorphic markers, the rl（t） gene was ultimately mapped into a region of 11 kb flanked by the markers P95053 and Pl13.6 on chromosome 2. The genetic distance of this region is about 0.04 cM. Only one predicated ORF （open reading frame）/gene was found in this region, which encodes a transcription factor of the homeobox family HD-GL2 （also known as HD-ZIP Ⅳ ）. The results laid a foundation for further cloning of rl（t） and understanding of its reguiation mechanism.