Electron Microscope studies (TEM and SEM) of in vitro multiplication of Lavandula stoechas L.: I. regeneration from seedling shoot apex explants

Abstract

Available data concerning “in vitro” multiplication of Lavandula sps. are scarce and do not involve cytological studies. In this work, shoot initiation from shoot apex explants of Lavandula stoechas is analysed, for the first time, in light and electron microscopes (TEM, SEM). Following habitual sterilization, seeds of Lavandula stoechas were germinated on MS basal medium with 2% sucrose (W/v). From 9-days old seedlings, explants (shoot tips including a small distal segment of hypocotyl - fig. 1) were aseptically excised and cultivated in that basal medium added with organic components as in B5 medium of Gamborg et al., 10% (V/v) of coconut milk, 0.8% of agar and benzyl-amino-purine (BAP) at different concentrations (0-4 mg/1). The pH was adjusted to 5.6 and cultures were maintained at 25±1°C with fluorescent light (2000 lux) for 16 h/day.High frequency of multiple shoot formation was achieved on media supplemented with BAP, the concentration of 1mg/l showing to be the optimal one (Table 1).