Study of flowering in pistacia vera l. C.v. Ovhady

Due to the importance of flower initiation and further development of flower buds in fruit set and yield, this research was conducted to explore flower formation and differentiation of mature Ovhady cultivar as one of commercial pistachio cultivars. Flower buds of this cultivar were collected during 10 months period and fixed using FAA. After preparation of the microscopic slice and staining, microscopic observation based on Tunica-Corpus hypothesis revealed that when vegetative bud moves towards differentiation, the number of cells decreased in Tunica Zone. Observation of morphologic changes were detected the initiation of rachis formation was at the end of April and completed in June. Differentiation of pistil started in September and visualized in October. Flower buds had not any growth in winter. Floral primordia (Pistillate) produced quickly three carpels and will be ready for anthesis at the end of March. In conclusion, the results from the present study of pistachio flower physiology will be used to facilitate pistachio orchard management.