《植物生理学报》 2018, 54(7): 1186-1194

贵州地方粳稻‘黎平杂边禾’矮秆小粒突变体dss1鉴定与基因定位

曾晓芳¹, 黄仁权¹, 陈锡², 李岩¹, 李建容¹, 赵德刚^1,2,*

¹贵州大学农业生物工程研究院/生命科学学院, 山地植物资源保护与种质创新教育部重点实验室, 贵州省农业生物工程重点实验室, 贵阳550025; ²贵州省农业科学院, 国家DUS中心贵州分中心, 贵阳550006

通信作者：赵德刚；E-mail: dgzhao@gzu.edu.cn

摘　要：

本研究从贵州地方粳稻(Oryza sativa ssp. japonica)品种‘黎平杂边禾’甲基磺酸乙酯(EMS)突变体库中筛选获得一份能稳定遗传的矮秆小粒突变体, 暂命名为dss1 (dwarf and small seed 1)。与野生型相比, dss1表现为植株矮化、株型直立、叶色深绿、籽粒变小、第二节间严重缩短、穗长增加等典型油菜素内酯(BR)缺陷突变体的性状。显微观察结果表明dss1叶鞘表皮细胞的长度变短, 可能是突变体第二叶鞘长度比野生型短的原因。对突变体的暗形态建成与BR敏感性研究表明, 黑暗条件下突变体表现为去黄化表型, 对外源BR敏感。遗传特性分析证明dss1突变体由一个隐性单基因位点控制。利用MutMap技术将dss1基因定位于3号染色体上, 筛选获得一个候选基因, 测序结果表明, dss1候选基因为BR合成途径关键酶基因OsDWARF, dss1是由于该基因第5个外显子上第335位的氨基酸由苏氨酸(ACT)突变为异亮氨酸(ATT)所引起的。定位得到的矮化小粒基因DSS1为一个新的OsDWARF等位基因。

关键词：水稻; 矮化小粒突变体dss1; 基因定位; OsDWARF基因; 油菜素内酯

收稿：2018-04-09   修定：2018-06-05

资助：国家转基因生物新品种培育科技重大专项(2016ZX08-010003)、贵州省科技重大专项(黔科合重大专项字[2012]6005)和贵州省高层次创新型人才培养项目[黔科合人才(2016)4003号]。

Identification and gene mapping of a dwarf and small seed mutant dss1 in ‘Lipingzabianhe’, a japonica rice landrace in Guizhou

ZENG Xiao-Fang¹, HUANG Ren-Quan¹, CHEN Xi², LI Yan¹, LI Jian-Rong¹, ZHAO De-Gang^1,2,*

¹Institute of Agro-bioengineering / College of Life Sciences, Key Laboratory of Plant Resources Conservation and Germplasm Innovation in Mountainous Region (Ministry of Education), Guizhou Key Laboratory of Agro-bioengineering, Guizhou University, Guiyang 550025, China; ²Guizhou Academy of Agricultural Sciences, Guiyang Station for DUS Testing Center of New Plant Varieties of MOA, Guiyang 550006, China

Corresponding author: ZHAO De-Gang; E-mail: dgzhao@gzu.edu.cn

Abstract:

A stably inherited dwarf and small seed mutant dss1 was identified from ethyl methane sulfonate (EMS) mutant progeny of ‘Lipingzabianhe’, a rice (Oryza sativa ssp. japonica) landrace in Guizhou. Compared to wild type (WT), dss1 mutant showed the typical brassinosteroid (BR)-deficient phenotype, with erect and dark green leaves, small seeds, un-elongated second internodes and longer panicles. The leaf sheath epidermal cells were shorter than those of the wild types. To determine whether the dwarf phenotype of mutant plants was caused by BR deficiency or insensitivity, we analyzed the response of dss1 to exogenous BR treatment and skotomorphogenesis. The results suggest that the dss1 plant showed a deetiolated phenotype in the darkness, and was sensitive to exogenous BR. Genetic analysis and F₂ progeny segregation results reveal dss1 was controlled by a pair of recessive genes. By employing the MutMap method, we revealed that dss1 contains a mutation in the OsDWARF gene on chromosome 3. The dss1 mutation occured in the 5th exon of OsDWARF, which caused a nonsense mutation of a threonine (ACT) codon change to an isoleucine (ATT) at residue 335. We confirmed that DSS1 mapped in this study is a new allelic gene of OsDWARF.

Key words: rice; dwarf and small seed mutant dss1; gene mapping; OsDWARF gene; brassinosteroids