Examination of Flower Bud Initiation and Differentiation in Sweet Cherry and Peach by Scanning Electron Microscope

Authors: HAKAN ENGİN, ALİ ÜNAL

Abstract: Flower initiation and development in 0900 Ziraat sweet cherry (Prunus avium L.) and Glohaven peach (Prunus persica L.) were examined using scanning electron microscopy. The objectives were to determine the timing of floral developmental stages and to achieve a better understanding of the morphological changes during flower formation at the apex of axillary buds of sweet cherry and peach cultivars. In cherry, bud samples were taken every 10 days from June 26 to August 24 and stored in formalin, 70% ethanol, and acetic acid solution (10:50:5, by volume). In peach, bud samples were collected every 10 days from June 28 to September 16 and stored in the same solution. In cherry, on July 5, 85 days after anthesis (DAA), a swelling of the apex signified the initial change from the vegetative to the reproductive stage. Flower primordia differentiated in the axils of bracts on July 15. Sepal primordia were evident on July 25, 15 weeks after anthesis, and petal primordia had formed by August 4. Concentric rings of stamen primordia differentiated between August 4 and 24, followed by the pistil. These organs of the flower attained their normal forms by the end of August. In peach, on July 8, 109 DAA, a flattened apex signified the initial change from the vegetative to the reproductive stage. After this stage, floral primordia developed in the order of sepal, petal, stamen, and carpel. Sepal primordia were evident on August 17, 149 DAA, petal primordia were evident on August 27, 159 DAA, and rings of stamen primordia had formed by September 16, followed by the carpel. These organs of the flower attained their normal forms by the end of September.

Keywords: Floral formation, flower primordia, Prunus avium, Prunus persica, Rosaceae

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