Identification of a novel tillering dwarf mutant and fine mapping of the TDDL(T) gene in rice (Oryza sativa L.)  

作　　者：GAO ZhenYu LIU XiaoHui GUO LongBiao LIU Jian DONG GuoJun HU Jiang HAN Bin QIAN Qian 

机构地区：[1]State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou 310006, China [2]National Center for Gene Research, Chinese Academy of Sciences, Shanghai 200233, China

出　　处：《Chinese Science Bulletin》2009年第12期2062-2068,共7页

基　　金：Supported by National Natural Science Foundation of China(Grant Nos.30400255,30623006);National High Technology Research and Development Program of China(Grant Nos.2006AA10A102,2006AA10Z1B5)

摘　　要：Rice plant architecture is an important agronomic trait that affects the grain yield. To understand the molecular mechanism that controls plant architecture, a tillering dwarf mutant with darker-green leaves derived from an indica cultivar IR64 treated with EMS is characterized. The mutant, designated as tddl(t), is nonallelic to the known tillering dwarf mutants. It is controlled by one recessive nuclear gene, TDDL(T), and grouped into the dn-type dwarfism according to Takeda's definition. The dwarfism of the mutant is independent of gibberellic acid based on the analyses of two GA-mediated processes. The independence of brassinosteroid (BR) and naphthal-3-acetic acid (NAA) of the tddl(t) mutant, together with the decreased size of parenchyma cells in the vascular bundle, indicates that the TDDL(T) gene might participate in another hormone pathway. TDDL(T) is fine mapped within an 85.51 kb region on the long arm of rice chromosome 4, where 20 ORFs are predicted by RiceGAAS (http://ricegaas.dna.affrc. go.jp/rgadb/). Further cloning of TDDL(T) will benefit both marker assisted selection (MAS) of plant architecture and dissection of the molecular mechanism underlying tillering dwarf in rice.Rice plant architecture is an important agronomic trait that affects the grain yield. To understand the molecular mechanism that controls plant architecture, a tillering dwarf mutant with darker-green leaves derived from an indica cultivar IR64 treated with EMS is characterized. The mutant, designated as tddl（t）, is nonallelic to the known tiilering dwarf mutants. It is controlled by one recessive nuclear gene, TDDL（T）, and grouped into the dn-type dwarfism according to Takeda＇s definition. The dwarfism of the mutant is independent of gibberellic acid based on the analyses of two GA-mediated processes. The independence of brassinosteroid （BR） and naphthal-3-acetic acid （NAA） of the tddl（t） mutant, together with the decreased size of parenchyma cells in the vascular bundle, indicates that the TDDL（7） gene might participate in another hormone pathway. TDDL（T） is fine mapped within an 85.51 kb region on the long arm of rice chromosome 4, where 20 ORFs are predicted by RiceGAAS （http：//ricegaas.dna.affrc. go.jp/rgadb/）. Further cloning of TDDL（T） will benefit both marker assisted selection （MAS） of plant architecture and dissection of the molecular mechanism underlying tillering dwarf in rice.

关 键 词：矮秆突变体 隐性核基因 水稻植株 精细定位 ORYZA 分蘖 鉴定 环境管理体系 

分 类 号：S511.03[农业科学—作物学] S642.203