A Novel Locus for Bakanae Disease Resistance, qBK4T, Identified in Rice

Bakanae disease caused by Fusarium fujikuroi causes crop failure and yield losses in the majority of rice-growing countries. In this study, we employed a joint strategy quantitative trait locus (QTL) mapping–Genome-Wide Association Study (GWAS) to investigate novel genetic loci associated with Bakanae disease resistance using a population of 143 BC1F8 RILs derived from a cross between Ilpum × Tung Tin Wan Hien1. The phenotypic data from the bioassay and the genotypic data generated using a DNA chip were utilized to perform QTL mapping and GWAS study. Our results identified a novel genetic locus qBK4T associated with Bakanae disease resistance, which was mapped on chromosome 4 and flanked by AX-116847364 (33.12 Mbp) and AX-115752415 (33.44 Mbp) markers covering a region of 324kbp. There were 34 genes in this region including Os04g55920 (encoding a zinc-finger protein, OsJAZ1), Os04g55970 (encoding AP2-like ethylene-responsive transcription factor), etc. This study proposes qBK4T as a novel locus for Bakanae disease resistance. The identification of qBK4T and its flanking marker information could be useful for marker-assisted breeding and functional characterization of resistance genes against bakanae disease.