摘要
水稻产量主要由单位面积有效穗数、每穗粒数和粒质量决定,其中粒质量主要受籽粒形态的影响。鉴定并克隆调控粒型的新基因,对完善粒型调控机制和提高水稻产量有重要意义。从籼稻保持系西大1B(XD1B)的甲基磺酸乙酯(ethylmethanesulfonate,EMS)诱变库中鉴定到1个小籽粒突变体(small grain 5,smg5),与野生型相比,smg5突变体籽粒极显著变小,植株矮化、穗型直立。组织细胞学分析显示:smg5突变体的小籽粒表型与颖壳细胞扩展和细胞增殖异常有关,导致细胞数目和面积减小。遗传分析表明:smg5突变体性状受1对隐性单基因控制。通过MutMap将SMG5定位在水稻第7条染色体上27.5~29.2 Mb中,结合重测序和PCR测序结果,发现突变体中LOC_Os07g47950的第5个外显子的第37位发生了C-T单碱基替换,导致氨基酸由苏氨酸(Thr)变为异亮氨酸(Ile)。该位点在F 2代突变表型和野生表型植株的突变率分別为100%和15%,因此可将SMG5的候选基因暂定为LOC_Os07g47950。
Rice yield is mainly determined by effective panicle number per unit area,grains per panicle and grain weight,in which grain weight is mainly influenced by grain size.Identifying and cloning the new genes regulating grain size is of great significance for improving the regulation mechanism of grain size and increasing rice yield.This study reported a small grain mutant named small grain 5(smg5)identified from the mutagenesis population of an indica rice maintainer line Xida1B(XD1B)induced by ethyl methane sulfonate(EMS).Compared with the wild type,smg5 mutant exhibited significantly smaller grains along with dwarf plant and erect panicles.Histocytological analysis showed that the small grain phenotype of smg5 mutant was related to the abnormal expansion and proliferation of the glume cells,which led to decreased cell number and size.Genetic analysis showed that the trait of smg5 mutant was controlled by a pair of recessive single gene.SMG5 was mapped to a region of 27.5-29.2 Mb on chromosome 7 by MutMap.Moreover,re-sequencing and PCR sequencing identified a C-T single base substitution at the 37 th base of the fifth exon of LOC_Os07g47950 from the mutant,resulting in an amino acid change from threonine(Thr)to isoleucine(Ile).The mutation rate of this SNP in the mutant and wild phenotype plants of the F2 population was 100%and 15%,respectively.Therefore,the LOC_Os07g47950 was tentatively identified as the candidate gene of SMG5.
作者
彭瀚平
郑馨媛
刘鉴瑶
刘墨言
朱洪慧
李映姿
雷良喆
曹晨
张婷
李云峰
庄慧
PENG Hanping;ZHENG Xinyuan;LIU Jianyao;LIU Moyan;ZHU Honghui;LI Yingzi;LEI Liangzhe;CAO Chen;ZHANG Ting;LI Yunfeng;ZHUANG Hui(Rice Research Institute,Southwest University/Academy of Agricultural Sciences/Key Laboratory of Application and Safety Control of Genetically Modified Crops,Chongqing 400715,China;Yibin Academy of Southwest University,Yibin Sichuan 644000,China)
出处
《西南大学学报(自然科学版)》
北大核心
2025年第7期33-46,共14页
Journal of Southwest University(Natural Science Edition)
基金
重庆市现代农业产业技术体系项目(CQMAITS202301)
四川科技局项目(2024NSFSC0321)
四川省科技计划项目(2024JDRC0064)
国家级大学生创新创业训练计划项目(202410635113)
重庆市大学生创新创业训练计划项目(S202410635012)。
关键词
水稻
小籽粒突变体
表型鉴定
基因定位
rice(Oryza sativa L.)
small grain mutant
phenotype identification
gene mapping
作者简介
彭瀚平,硕士研究生,主要从事水稻籽粒形态发育分子机制研究;通信作者:庄慧,博士,副教授,硕士研究生导师。
