Abstract

In this study, morphological and physiological changes in flower development of the rose (Rosa hybrida L.) in the garden were analyzed. Role of plant growth regulators on in vitro floral organogenesis of rose from floral meristem was investigated. The flowering of Rosa hybrida L. has three phases: shoot apical meristem, single floral meristem and floral bud with sepals, petals, stamens and gynoecium. Activities of cytokinins and auxins increased in the transition of shoots from vegetative growth to floral initiation stage. Floral meristems having sepals and the first layer of petals on MS medium with 0.5 mg/L GA3, 0.1 mg/L NAA and 0.3 m/L BA were continuously developed in these next layers of petals and became floral buds at the highest percentage after 4 and 8 weeks of culture, respectively.