Abstract
Dioecy, the presence of male and female individual, has evolved independently from hermaphroditism in multiple flowering plant lineages. Spinach, an important leafy vegetable crop worldwide, is a dioecious species with an XY sex-determination system. Although some markers that are fully linked to male-determination locus were identified, the male-specific region (MSR) remained unclear. In this research, five male individuals and five female lines were resequenced to identify the male-specific region. We identified a region (~21 kb) on chromosome 4 (putative sex chromosome) where the five females had a low reads coverage, while the five males had high coverage. A KASP marker, SponR, developed from a single nucleotide polymorphism (SNP) closely linked to the MSR was co-segregating with the sex determination gene in the population of 958 individuals, suggesting that the MSR might be specifically present in male spinach plants.
