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-Papaya (Carica papaya L., 2n = 18), a polygamous angiosperm, is a major fruit crop in tropical and subtropical regions. It is trioecious with three sex forms: male, female, and hermaphrodite, where sex determination is controlled by the XY chromosome pair with two slightly different Y chromosomes i.e. Y for male and Y h for hermaphrodite. Sex type determination in papaya, which cannot be determined either by embryo shape or morphology at the juvenile developmental stage, is an essential pre-requisite for crop improvement processes as it helps in identifi cation of fruitful plants. Hence, molecular profi ling could be used as an alternative that provides a quick and reliable identifi cation of sex types in plantlets at initial stages only. In the present study we have validated the sexlinked sequence characterized amplifi ed region (SCAR) marker W11 using PCR detection assay among different cultivars of papaya i.e. dioecious with either female or male and gynodioecious with either female or hermaphrodites and also performed a double-blind test for validating the seedlings of 84 F1 plants, which resulted in their sex determination. The assay clearly gives 800 bp band in male plants in dioecious types and hermaphrodite in gynodioecious plants.

The technique of SSR amplification is a prerequisite to generate the molecular profiles of various alleles of an individual or genotype. Amplification is the multifold duplication and accumulation of a targeted region which is achieved by polymerase chain reaction. It needs ingredients such as buffer, MgCl2, dNTPs, primers, and DNA polymerase enzyme. The utilization of these essential PCR components in optimal concentrations determines the success of amplification. Thus SSRs, as primers, play an important role in enhancing the amplification and thereby generating the genotype profile. With the advent of technology, fluorophore-labeled primers along with automated capillary electrophoresis system have enhanced the efficiency of detection.