Relationship between petiole distribution and flower type in Maradol-type papaya populations

Abstract

Determining the sex of papaya plants is complex, as flowers can be male, female, or hermaphroditic, which affects fruit production and quality. Identifying the sex of seedlings before flowering is key to optimizing resource use in the field. However, sex determination using molecular methods such as PCR (Polymerase Chain Reaction), while accurate, is costly and requires specialized infrastructure. Furthermore, the use of traditional methods based on morphology is confusing. On the other hand, the direction of petiole twist associated with flowering has not been studied. In some plants, the petiole twists clockwise or counterclockwise, which could be related to the plant’s sex. The aim of this study was to determine the relationship between the direction of petiole twist and plant sex in selections of ‘Maradol’ papaya genotypes. Plants were observed during the flowering/fruiting stage, and the direction of petiole twist and flower type were recorded. Inferential statistics were used with the four possible combinations of petiole twist and plant sex: right (R)/female(F); right(R)/hermaphrodite(H); left(L)/female(F); left(L)/hermaphrodite (H). The analysis showed that leftward twisting was most strongly associated with hermaphroditic plants. Specifically, this twisting pattern has a 72 % probability of occurring in hermaphroditic flowers, whereas rightward twisting is more likely to be found in female flowers. This finding makes it possible to predict the flower type before blooming based on the twisting of the petiole, thereby facilitating the identification of hermaphroditic plants.