<b>S</b><b>heath </b><b>b</b><b>light-</b><b>r</b><b>esistant </b><b>r</b><b>ice </b><b>g</b><b>ermplasm YSBR1</b>

Sheath blight is a globally prevalent major disease in rice. In earlier stages of this research, a highly sheath blight-resistant germplasm, YSBR1, was developed from progeny of indica-japonica crosses. However, its genomic composition has remained unclear, limiting resistance gene discovery. Utilizing sequencing technologies such as PacBio HiFi, ONT ultra-long, and Hi-C, this study constructed a complete telomere-to-telomere (T2T) genome for YSBR1, identifying 37,750 genes, of which 2,763 are unique to YSBR1. Comparative genomics revealed a mosaic genome composition: 60.31% indica, 22.27% japonica, 4.98% Aus, 3.94% aromatic, and 8.51% inter-subgroup conserved sequences. We propose that introgressed genomic regions converged superior alleles, potentially driving its high resistance. This work establishes a genomic resource to unravel sheath blight resistance mechanisms and mine agronomically vital genes from YSBR1.