EVALUATION OF GENETIC MARKERS FOR DISCRIMINATION BETWEEN FEMALES AND HERMAPHRODITES OF PAPAYA (Carica papaya L.) CV. ‘MARADOL’

Abstract

Papaya (Carica papaya L.) shows three sexual types: male, female and hermaphrodite, from which only the last one has commercial value and export quality. Morphologically, such types are only distinguishable starting at flowering stage. Sex segregation in this species is explained by a multiallelic locus, even though it is more complex at the molecular level. In ‘Maradol’ papaya, the female and hermaphrodite types are almost the only present sexual forms, so that the distinction between these two forms is sought. In this work, three sets of SCAR primers, previously developed for Hawaiian varieties, were tested. The three markers are identified as T1, T12 and W11. From tissue of 17 female and 23 hermaphrodite plants, it was found that the markers T12 and W11 showed 100 % specificity for hermaphrodite individuals, with null amplification for female plants. On the other hand, the T1 SCAR primers amplified DNA only in some hermaphrodite plants. It is concluded that T12 and W11 SCAR markers can be used as a part of a technique to identify plant sex in early stages of ‘Maradol’ papaya for commercial cultivation purpose, after validation with other populations of the same variety.