Genetic analysis and gene mapping of a new narrow-leaf mutant in rice （oryza sativa l.） | 一个新的水稻窄叶突变体的遗传分析和基因定位

Chinese. 摘　　要：水稻叶片形态相关突变体是水稻功能基因组学研究和株型改良的重要材料。本研究以新的窄叶突变体MR11为研究材料,发现该突变体在整个生育期表现为窄叶、叶长变短和植株矮化。叶片组织结构观察发现由于叶脉数减少和叶脉间宽度减小,导致突变体倒二叶叶片宽度不及野生型的1/2。F2和BC1F1两个群体分离结果表明该窄叶突变体表型受一对隐性核基因控制。选用F2群体采用图位克隆法进行基因定位,被定位在第4号染色体长臂上的SSR标记RM17486和RM6629之间,遗传距离分别为0.3cM和2.8cM。序列分析证明MR11窄叶性状不是由已克隆的NAL1引起,该基因虽与NAL1位于同一染色体区段,是一个新的窄叶基因,暂命名为nal1（t）。

English. The exploration of new genes controlling rice leaf shape is an important foundation for rice functional genomics and plant architecture improvement. In the present study, a new narrow-leaf mutant MR11, which exhibits the characteristic phenotype of narrow leaves, short leaves and dwarf at whole growth stages, has been identified. In accordance with reduced leaf blade width, leaves of MR11 contain a decreased number of longitudinal veins and narrow width between the small veins, the width of the reverse 2nd leaf in the mutant was less than 1/2 that of its wild type. Two populations, F2 and BC1F1 were used for genetic analysis, the result revealed that the phenotype was controlled by a pair of single recessive nuclear gene. The F2 population was used for mapping this gene by map-base cloning method, and result showed the gene is located between two simple sequence repeat （SSR） markers RM17486 and RM6629 on the long arm of chromosome number four, with genetic distances 0.3 cM and 2.8 cM, respectively. Sequence analysis showed that the phenotype of narrow leaves is not caused by the known gene NAL1, this gene is a new narrow-leaf gene, although located at the same chromosome segment with NAL1, that was tentatively designated as nal1（t）.