Evaluation of the micropropagation of hairless catmint (Nepeta nuda L.), an endangered medicinal plant

Aim: The aim of this study was to investigate the effects of different treatments of growth regulators on the amount of shooting, rooting, callus production and plant regeneration of hairless catmint (Nepeta nuda), in vitro condition.
Material and The seeds of this plant were cultured in MS/2, and then the plantlets were sub-cultured. The obtained samples were cultured in different levels of BA and Kinetin, either alone or in combination with IBA. Leaves of explants were used for callus induction with BA and NAA treatments in both medium (light and dark). Also, for regeneration, the same calluses were used with BA and NAA treatments.
The results of this study showed that, in proliferation part, the highest fresh weight (2315.9 mg) and shoot number (15.22 per each bush) of each plantlet were obtained in 1 mgL-1 BA and 0.25 mgL-1 IBA. Moreover, the BA treatment with 2 mgL-1 concentration cause to produce the longest branches (50.5 cm) and the highest number of nodes (53.6 per plantlet) in each plantlet.
The highest length, number and percentage of root were obtained at MS/2 medium and 0.5 mgL-1 IBA. In callus formation part, the highest fresh weight of callus was related to application of 1 mgL-1 BA with 0.5 mgL-1 NAA. In addition, the highest percentage of callus formation was observed in dark medium and no significant differences were observed between the growth regulator treatments. Furthermore, the highest percentage of regeneration of callus related to both growth regulators treatments included 1 mgL-1 BA with 0.2 mgL-1 NAA (83.2 %) and 1 mgL-1 BA with 0.5 mgL-1 NAA (81.66 %) with no significant differences between them.
In total, the most useful growth regulator compound for micro-propagation of hairless catmint, which is endangered extinction species, were 1 mgL-1 BA with 0.5 mgL-1 IBA and NAA.