The application provides a multi-
omics gene mining technology-based method for detecting and regulating
rice grain length GW5 The application relates to the technical field of
biology, and relates to application of
gene promoter methylation in regulation of
rice grain length. The application is based on a pan-
genome micro-core
germplasm population, integrates multi-dimensional
omics data such as genomes and epigenomes, constructs an
epigenome atlas of rice, and uses stable
methylation polymorphic markers in the atlas to combine with a
rice grain width
phenotype to perform multi-
omics correlation analysis, successfully mines a new epiallele of a
gene, discovers GW5 a new epiallele of a gene, and discovers GW5 that a high-
methylation and low-methylation epigenetic state exists in an upstream
promoter region of the gene in different rice
germplasm backgrounds, and that after
demethylation editing is performed on the region, a
phenotype of significantly increased grain length is exhibited. Therefore, according to GW5 a methylation level of a
promoter of the gene, detection of a rice grain length trait can be realized, and by regulating GW5 a methylation level of a promoter of the gene, regulation of a rice grain length trait can be realized.