title: Mapping of the genes for dioecism and monoecism in Spinacia oleracea L.: evidence that both genes are closely linked.
abstract: Spinach is basically a dioecious species, with occasional monoecious plants in some populations. Sexual dimorphism in dioecious spinach plants is controlled by an allelic pair termed X and Y located on the short arm of the longest chromosome (x = 6). Ten AFLP markers, closely linked to the X/Y locus, were identified using bulked segregant analysis, four of which were revealed to co-segregate with Y in the present mapping population. We mapped the AFLP markers and two known male-specific DNAs to a 13.4 cM region encompassing the locus. These markers will be the basis for positional cloning of the sex-determination gene. We also showed that a single, incompletely dominant gene is responsible for the highly staminate monoecious character. The gene was found to be located at a distance of 4.3 cM from microsatellite marker SO4, which mapped 1.6 cM from the X/Y locus. This indicates that the monoecious gene seems not to be allelic to but closely linked to the X/Y gene pair. SO4 will enable breeders to efficiently select highly male monoecious plants for preferential use as the pollen parent for hybrid seed production.
authors.affiliation: Laboratory of Genetic Engineering, Research Faculty of Agriculture, Hokkaido University, N-9, W-9, Sapporo 060-8589, Japan.
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Onodera
authors.forename: Itaru
authors.initials: I
authors.lastname: Yonaha
authors.forename: Hiroki
authors.initials: H
authors.lastname: Masumo
authors.forename: Atsushi
authors.initials: A
authors.lastname: Tanaka
authors.forename: Satoshi
authors.initials: S
authors.lastname: Niikura
authors.forename: Seishi
authors.initials: S
authors.lastname: Yamazaki
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Mikami
mesh_terms: D054458:Amplified Fragment Length Polymorphism Analysis; D002874:Chromosome Mapping / Q000379:methods*; D020090:Chromosome Segregation / Q000235:genetics; D032461:Chromosomes, Plant / Q000235:genetics; D003433:Crosses, Genetic; D017343:Genes, Plant / Q000235:genetics*; D008040:Genetic Linkage; D056426:Genetic Loci / Q000235:genetics; D005838:Genotype; D040582:Inheritance Patterns / Q000235:genetics; D018895:Microsatellite Repeats / Q000235:genetics; D016133:Polymerase Chain Reaction; D018724:Spinacia oleracea / Q000235:genetics*