In Vitro Propagation of Rosemary (Rosmarinus officinalis L.): Effects of BAP and NAA Concentrations on Shoot Proliferation, Morphogenesis, and Regeneration
Zilola Abdugafforova1 
, Bakhtiyor Ganiyev2* , Sevda Aliyeva3
Abstract. Rosemary (Rosmarinus officinalis L.) is an economically and medicinally important aromatic shrub widely recognized for its richness in essential oils, phenolic diterpenes, and antioxidant constituents. Traditional propagation techniques often produce genetically variable plant material and are unable to supply sufficient quantities to satisfy industrial demand, highlighting the need for efficient and reproducible in vitro propagation systems. In this study, the effects of two cytokinin–auxin combinations on the growth, organogenesis, and morphogenetic responses of rosemary nodal explants cultured on Murashige and Skoog (MS) basal medium were evaluated. The treatments included 1.0 mg/L 6-benzylaminopurine (BAP) combined with 0.5 mg/L naphthaleneacetic acid (NAA) (T1), and 2.0 mg/L BAP combined with 0.5 mg/L NAA (T2). Explants were incubated under a 15-hour photoperiod with a 7-hour dark cycle at 24–26 °C, following an initial 72-hour dark preconditioning period. After four weeks of culture, T1 resulted in uniform shoot development with minimal or no callus formation, whereas T2 promoted a higher rate of shoot proliferation but induced incipient callus formation in approximately 25% of explants. These results indicate that the balance between cytokinin and auxin strongly influences regeneration behavior in rosemary, with 1.0 mg/L BAP providing more stable morphogenetic outcomes suitable for large-scale micropropagation, while 2.0 mg/L BAP may be applied when rapid shoot multiplication is prioritized under controlled conditions ensuring genetic stability.
Keywords: Rosmarinus officinalis L., in vitro propagation, micropropagation, MS medium, 6-benzylaminopurine, naphthaleneacetic acid, organogenesis, callus formation, plant tissue culture, essential oils, phytohormones, secondary metabolites