浅绿叶水稻突变体的特性与遗传分析  

Genetic Analysis and Characteristics of Pale-green Leaf Rice Mutant

作　　者：胡巍[1] 高云[1] 张强 张彬[1] 江奕君[1] HU Wei;GAO Yun;ZHANG Qiang;ZHANG Bin;JIANG Yi-jun(Guangdong Provincial Key Laboratory of New Technology in Rice Breeding/Institute of Rice Research,Guangdong Academy of Agricultural Sciences,Guangzhou 510460)

机构地区：[1]广东省水稻育种新技术重点实验室/广东省农业科学院水稻研究所,广州510460

出　　处：《植物遗传资源学报》2021年第1期194-204,共11页Journal of Plant Genetic Resources

基　　金：广东省科技计划项目(2016A020210040,2017A070702006)。

摘　　要：在簇生稻与粳稻日本晴杂交后代F8世代中发现一个能稳定遗传的浅绿叶色突变体(pgl,pale green leaf)。与野生型相比,突变体pgl株高、剑叶宽、主穗粒数和千粒重均显著下降。从幼苗开始,突变体pgl叶片都表现为浅绿色。在苗期和抽穗期突变体叶片的叶绿素含量都极显著低于野生型,其中叶绿素b的含量极低,仅为0.002~0.003 mg/g,突变体pgl表现为叶绿素b的缺失。在分蘖期与齐穗期,突变体pgl的净光合作用速率与野生型相当。叶绿体超微结构观察表明突变体pgl的叶绿体基质片层和堆叠层数较少。遗传分析发现浅绿叶色表型由一对隐性细胞核基因控制。采用BSA法,通过全基因组SNP芯片分析,浅绿叶色基因pgl被定位于水稻第10染色体上的22806614~23000408区间,与R1022900951CA标记紧密连锁。突变体pgl与另外3个浅绿叶色突变体(W1、Y406和Y45)的等位性检测结果表明浅绿叶色基因pgl与突变体W1的浅绿叶色基因为等位基因。对pgl的候选基因LOC_Os10g41780(叶绿素a加氧酶,chlorophyll a oxygenase)的序列比对发现,在突变体pgl中,LOC_Os10g41780在第2507和3136位碱基处分别发生1个T的缺失和T变成C的替换。分析发现,第3136位碱基位于第9外显子内,其碱基T变C的替换导致其编码的精氨酸变成色氨酸。本研究鉴定的突变体pgl和W1为LOC_Os10g41780的新变异,为阐明浅绿叶色形成的分子机理和光合作用机理的研究提供了特异资源。This study identified a pale-green leaf(pgl)mutant in F8 generation of clustered-spikelet rice crossed with Japonica rice Nipponbare.The pgl mutant with the pale-green leaf at all the growth stages,represented significant reduction on plant height,flag leaf width,number of seeds per main pancile and 1000-grain weight when compared with its wild type.The content of chlorophyll(Chl)b in pgl mutant is 0.002 to 0.003 mg/g,significantly lower than that in its wild type.The net photosynthetic rate of pgl mutant was the same as that of wild type plant at both tillering and full-heading stages.The ultrastructure analysis showed that the number of grana lamella of thylakoids in the pgl mutant were less than those in the wild type plant.The genetic analysis of the pgl mutant revealed one single recessive nuclear gene underlying the pigment phenotype.By whole-genome SNP-chip analysis using two bulks derived from the pale-green leaf plants and wild type plants in F2 segregating population respectively,pgl was located in the physical interval of 22806614 to 23000408 bp on the long arm of chromosome 10,linked with one SNP marker R1022900951CA,where the gene chlorophyll a oxygenase(CAO1,LOCOs10g41780)responsible for the synthesis of pigment is found.The allelism test between pgl and three pale-green mutants(W1,Y406 and Y45)proved an allelic nature between pgl and mutant W1.DNA sequence of CAO1 revealed one base pair deletion(T in 2507)and a T to C substitution in 3136 in pgl mutant,which results in a R to W substitution in the 9th exon.Collectively,this study provides new pale-green leaf mutants,which might be valuable in rice breeding and in the analysis of photosynthetic efficiency.

关 键 词：水稻 浅绿叶色 基因定位 

分 类 号：S511[农业科学—作物学]