INDUCTION OF PARTHENOCARPY IN Opuntia spp.

Abstract

Prickly pear (Opuntia spp.) is a fruit appreciated by consumers in Mexico and other countries; however, some people do not consume it because of numerous large seeds in the pulp, which affects its quality and limits its acceptance in the markets. This research determined the feasibility of producing quality parthenocarpic fruits in four varieties of prickly pear cactus widely used by farmers of Zacatecas and San Luis Potosi. Doses of 0, 50, 100 and 200 ppm of gibberellic acid (GA₃) were applied into emasculated flowers at the pre-anthesis stage to varieties Amarilla Montesa (Opuntia megacantha Salm-Dick), Burrona (Opuntia albicarpa Sheinvar), Cristalina (Opuntia albicarpa Sheinvar) and Rojo Pelón (Opuntia ficus-indica L.). Control flowers (0 ppm) pollinated freely. The experimental design was completely randomized, with 16 treatments resulting from a complete factorial arrangement with two factors and four levels for each factor (24). The experimental unit consisted of one flower. Applications were made in 20 flowers (replications) of different plants by treatment. Parthenocarpic fruits were obtained with the three doses of GA₃, with a significant reduction in their length, diameter and weight. GA₃ application reduced pulp weight, pulp weight/fruit weight ratio and ºBrix in both pulp and peel; in addition, the peel thickness increased in comparison to fruits produced from untreated flowers (control). Although the parthenocarpic fruits had little pulp and thicker peel, the latter had oBrix readings similar to those of the pulp, thus it is potentially edible.