Grain size plays a significant role in rice,starting from affecting yield to consumer preference,which is the driving force for deep investigation and improvement of grain size characters.Quantitative inheritance makes these traits complex to breed on account of several alleles contributing to the complete trait expression.We employed genome-wide association study in an association panel of 88 rice genotypes using 142 new candidate gene based SSR(cgSSR)markers,derived from yield-related candidate genes,with the efficient mixed-model association coupled mixed linear model for dissecting complete genetic control of grain size traits.A total of 10 significant associations were identified for four grain size-related characters(grain weight,grain length,grain width,and length-width ratio).Among the identified associations,seven marker trait associations explain more than 10％of the phenotypic variation,indicating major putative QTLs for respective traits.The allelic variations at genes OsBC1L4,SHO1 and OsD2 showed association between 1000-grain weight and grain width,1000-grain weight and grain length,and grain width and length-width ratio,respectively.The cgSSR markers,associated with corresponding traits,can be utilized for direct allelic selection,while other significantly associated cgSSRs may be utilized for allelic accumulation in the breeding programs or grain size improvement.The new cgSSR markers associated with grain size related characters have a significant impact on practical plant breeding to increase the number of causative alleles for these traits through marker aided rice breeding programs.

Amrit Kumar NAYAK;Anilkumar C;Sasmita BEHERA;Rameswar Prasad SAH;Gera Roopa LAVANYA;Awadhesh KUMAR;Lambodar BEHERA;Muhammed Azharudheen TP

Department of Genetics and Plant Breeding,Sam Higginbottom University of Agriculture,Technology and Sciences,Prayagraj 211007,India;Division of Crop Improvement,Indian Council of Agricultural Research-National Rice Research Institute,Cuttack 753006,India;Division of Crop Physiology and Biochemistry,ICAR-National Rice Research Institute,Cuttack 753006,India

水稻科学（英文版）

[1]Amrit Kumar NAYAK;Anilkumar C;Sasmita BEHERA;Rameswar Prasad SAH;Gera Roopa LAVANYA;Awadhesh KUMAR;Lambodar BEHERA;Muhammed Azharudheen TP-.Genetic Dissection of Grain Size Traits Through Genome-Wide Association Study Based on Genic Markers in Rice)[J].水稻科学（英文版）,2022(05):462-472,中插32-中插34

Genic,cgSSR,OsBC1L4,SHO1,OsD2,cgSSRs

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