Floral differentiation and development in early, middle and late blooming almond cultivars

Abstract

Flower initiation and development in almond (Prunus amygdalus L.) were examined with the objectives of determining the timing of floral developmental stages and achieving a better understanding of the morphological changes during flower formation at the apex of axillary buds of early, middle and late blooming almond cultivars. In almond trees, bud samples were taken every 10 days from May 31, 2007. Sample collection ended when more than 50% of the dissected buds had pistils initiated. Bud samples were stored in formalin, 70% ethanol, and acetic acid solution (10:50:5, by volume). Flower induction (flatting of doming meristem) were done in 8, 18 and 31 August of 2007 in middle blooming cultivar (A93), early blooming cultivar (H-2) and late blooming cultivar (Ferragnes), respectively. Sepals primordial were stimulated in A93, H-2 and Ferragnes cultivars in 24 and 31 August and in 13 September, respectively. Petals primordial induction in H-2, A93 and Ferragnes cultivars were done in 13, 15 and 17 September of 2007, respectively. Stamens primordia induction in H-2, A93 and Ferragnes were evident in that order 1, 10 and 20 October of 2007, respectively. The pistil primordium in H-2, A93 and Ferragnes were evident 10, 21 and 31 October of 2007, respectively. Anthesis was observed in H-2, A93 and Ferragnes in 7 and 21 March and in 5 April, 2008, respectively. In general, it was found that process floral formation stages in early, middle and late blooming almond cultivars particularly the timing of flower induction between cultivars was not similar. Key words: Flower primordia, Prunus amygdalus, flower initiation.