Determining the best combination of explant and plant growth regulators on callogenesis, indirect organogenesis, proliferation, and rooting of Lavandula officinalis L.

Lavender (Lavandula officinalis L.) is one of the rangeland species in the many parts of the world, which is cultivated as a medicinal and ornamental plant. Plant tissue culture techniques are an alternative method for the mass production of lavender colons and can overcome the problems caused by reproductive propagation. To determine the effect of different combinations and concentrations of growth regulators, and also explant type in the process of callogenesis, organogenesis, and rooting of lavender, a factorial experiment was conducted based on a completely randomized design with three replications. In this research, different responses to growth regulatory compounds were assessed at different stages. The best treatment for callogenesis was cotyledon explants in culture medium containing 0.5 mg/l 2.4-D along with 0.25 mg/l BAP. In indirect organogenesis, the highest number of branches and the rate of organogenesis were obtained in the medium containing 2 mg/l of KIN. Also, the highest number of branches was obtained from using 0.5 mg/l BAP treatment with 0.5 mg/l of KIN along with 0.1 mg/l IBA. The results showed that the best culture medium for rooting was the medium containing 1 mg/l IBA. The highest explants survival rate was related to using perlite and coco peat as a bed of cultivation. The finding of this research introduced an efficient regeneration system for this plant that can be used in rapid vegetative propagation, germplasm maintenance, and molecular modification programs through genetic engineering.