A genome-wide association study identifies candidate genes for fusarium wilt resistance in cucumber

Fusarium wilt (FW) caused by Fusarium oxysporum f. sp. cucumerinum Owen (Foc) is a devastating soil-borne fungal disease that significantly reduce cucumber yield and impairs fruit quality. Nevertheless, the genetic basis underlying cucumber resistance to FW remains poorly understood. In this study, 114 cucumber accessions were screened for FW resistance, identifying 11 resistant accessions. Notably, the Xishuangbanna ecotype exhibited resistance to FW, representing a valuable genetic resource for cucumber resistance breeding. Genome-wide association study (GWAS) analysis detected four loci ( gFOC1.1, gFOC2.1, gFOC6.1 , and gFOC6.2 ) significantly associated with FW resistance, distributed across three chromosomes. Based on integrated sequence analysis, haplotype evaluation, and expression profiling, six candidate genes for FW resistance were identified: CsaV4_1G002370, CsaV4_1G002372, CsaV4_2G000585, CsaV4_2G000590, CsaV4_6G002754, CsaV4_6G003082 . This study provides valuable genetic insights and resources for elucidating the molecular mechanism of FW resistance and for developing disease-resistant cucumber varieties.