Application of AFLP for the detection of sex-specific markers in hemp

Two dioecious hemp accessions (Can18 and Can17) were tested by bulked segre gant analysis for polymorphisms between male and female bulks with amplifie d fragment length polymorphisms. Thirty-nine primer combinations were teste d and 20 of these yielded one to three male-specific bands. In contrast, no female-specific band was detected. Eight of these primer combinations were used for testing 80 progeny plants from a cross between two plants from Ca n18 and 30 plants from Can17. A total of 16 and 17 male-specific fragments were obtained for Can18 and Can17, respectively. Eleven fragments exhibited the same fragment size in both accessions. All male plants, but not one fe male plant, showed the respective polymorphic band with each of the eight p rimer combinations. Problems regarding sex determination under field condit ions were successfully overcome by testing plants that had been grown in sm all pots in a greenhouse. The abundant number of potential markers for the male sex, their complete cosegregation with male plants and the absence of markers for the female sex support the presence of a male sex chromosome in hemp.