A SCAR marker for the sex types determination in Colombian genotypes of Carica papaya

Sex type determination in papaya (Carica papaya L.) is very important for crop improvement processes because it accelerates the identification of the fruitful plants. The use of molecular technology provides a quick and reliable identification of sex types in plantlets growing in seedbeds. Random amplified polymorphic DNA (RAPD) markers were used to determine the sex types of Colombian cultivars of dioecious papaya genotypes. This species has three sex types (male, female and hermaphrodite) determined by a multiallelic locus. There are no morphological differences at the chromosome level; therefore the identification of sex types by chromosomal dimorphism is not possible. A RAPD marker of 900 bp was found in male plants, but not in females or hermaphrodites. From this RAPD marker a sequence characterized amplified region (SCAR) was developed and it was possible to amplify fragments from the genomes of male and hermaphrodite plants, but not the female ones. The results indicate that this new SCAR marker will be valuable to determine the sex type of papaya plants.