南京农业大学学报2018，Vol.41Issue(1)：38-48,11.DOI:10.7685/jnau.201705034
水稻晚开花突变体lft1的鉴定与基因克隆
Identification and map-based gene cloning of a late flowering mutant lft1 in rice(Oryza sativa L.)
摘要
Abstract
[Objectives]Identification and genetic mapping of a rice late flowering mutant lft1(late flowering time)helps uncovering the underlying mechanism of photoperiodic regulation of rice flowering. [Methods]A'Nipponbare'T-DNA insertion mutant with late flowering time under long-day condition was selected. The relevance between late flowering and T-DNA insertion event was further established by analyzing lft1/Nipponbare F2population. Two F2populations,Nipponbare/9311 and lft1/9311 were investigated simultaneously and compared. Individuals with extremely late flowering time in lft1/9311 F2population were performed on gene mapping. The expression level of flowering time related genes was compared between the wild type Nipponbare and lft1 to clarify the gene role in network. [Results]Compared to wild type Nipponbare,lft1 delayed flowering about 20 days under long-day condition, accompanied by increase of grain length and 1 000-grain weight. After investigation in lft1/Nipponbare F2population,noco-segrega-tion with T-DNA insertion was observed and the late flowering trait was controlled by a pair of recessive gene. Compared with control F2population,extremely late flowering individuals were found,from which 58 were chosen for initial gene mapping. Genotyping of these individuals was performed by polymorphism markers developed between Nipponbare and 9311. The gene region was restricted on short arm of chromosome 9,flanked by molecular marker RM219 and RM3912,a length of 2.94 Mb region. In the process of further development of markers,we found that one molecular marker SJ9-32 can be detected by Nipponbare and 9311,but not by the lft1 and 58 extreme late flowering individuals. A large missing DNA segment covering SDG724 gene did exist. Anallelism test further confirmed that deletion in SDG724 was a causative factor of the late heading in lft1.The qRT-PCR results showed that SDG724 could regulate the expression of OsMADS51 and RFT1. [Conclusions]Due to the lack of SDG724 gene,corresponding expression levels of OsMADS51 and RFT1 were down regulated in lft1under long-day condition,therefore a late flowering trait was presented.It is feasible to adjust rice flowering by modulating the expression level of SDG724 gene,and this will work for rice breeding.关键词
水稻/晚开花突变体/分子鉴定/遗传分析/SDG724Key words
rice/late heading mutant/molecular identification/genetic analysis/SDG724分类
农业科技引用本文复制引用
许乐峰,万建民,许昕阳,张欢,赵志刚,郑天慧,赵婕妤,曾召琼,刘喜,陈赛华..水稻晚开花突变体lft1的鉴定与基因克隆[J].南京农业大学学报,2018,41(1):38-48,11.基金项目
国家重点研发计划项目(2016YFD0101801) （2016YFD0101801）
国家863计划项目(2014AA10A603-15) （2014AA10A603-15）
江苏省科技支撑计划项目(BE2015355-1) （BE2015355-1）
江苏省农业科技自主创新资金项目(CX(16)1029) （CX(16）
