Compatibilidad sexual entre dos tipos de Hylocerus (Cactaceae)

Dos de los tipos de pitahaya mas cultivados en la Península de Yucatán, México, difieren principalmente por el color de su cáscara, el primero es de color rojo (Uqroo1), perteneciente a Hylocereus undatus, mientras que en el segundo es color amarillo claro (Uqroo2), hasta el momento también identificado como H. undatus; este último es mas dulce. En ambos tipos de pitahayas, se realizaron autopolinizaciones y polinizaciones cruzadas directas y recíprocas, con el propósito de evaluar el efecto en la cantidad de frutos que lograron su desarrollo. Se midieron algunas variables para detectar la influencia del progenitor paterno en algunas características del fruto. Los testigos se obtuvieron de flores polinizadas libremente. El diseño experimental utilizado fue completamente al azar, con 15 repeticiones por tratamiento. Se encontró que Uqroo1 es autocompatible, mientras que Uqroo2 es autoincompatible. Los testigos de ambos tipos alcanzaron el mismo peso, y los frutos de Uqroo2 logrados por polinización cruzada tuvieron un peso similar al de los testigos o fueron significativamente mas pesados. Algunas variables resultaron positivamente correlacionados; el coeficiente entre el número de semillas y el peso total del fruto fue de r = 0.84. La correlación mas alta (r = 0.97) resultó entre el peso total y el peso de la pulpa. En los frutos obtenidos por polinización cruzada prevalecieron las características del progenitor materno. Se recomienda cultivar la Pitahaya blanca con otro tipo de pitahaya, además de Uqroo1<br>There are two types of pitahaya that are cultivated in Yucatan Peninsula of Mexico. They differ mainly in the skin color of the fruit, one of them has a red skin (Uqroo1), while the other has a light yellow skin (Uqroo2) both belong to Hylocereus undatus (Haworth) Britt. & Rose. The yellow skin pitahaya is the sweetest. The studies were conducted using the methods of self pollination and cross pollination, with direct crosses and reciprocal pollination in order to evaluate the effect related to the quantity of fruits that accomplish their growing process. Some characteristic parameters of fruits, thus obtained, were used to detect the possible xenic effect. The control samples were collected from naturally pollinated flowers. The experimental design used was completely random and the experiment was repeated fifteen times. The results revealed that the Uqroo1 turned out to be self-compatible, and their fruits reached one hundred percent of development. On the other hand, Uqroo2 was self-incompatible, that is, it did not accept self pollen. The control samples of both types reached the same weight, and the fruits of the Uqroo2 produced by cross pollination had the same or more weight than the control samples. Several parameters were positively correlated. The coefficient between the number of seeds and the fruit weight was r= 0.84. The highest correlation that was found (r = 0.97) in the fruit weight and the pulp weight within both types. The fruits obtained by cross-pollination maintained the characteristic of the female progenitor. It is suggest intercalate the yellow pitahaya plants with another types or species of pitahaya, other than the Uqroo1