In vitro control of adventitious bud differentiation by inorganic media components in leaves of matureJuniperus oxycedrus

The effects of changes in the concentration of macronutrients on BA-induced caulogenesis from leaves of matureJuniperus oxycedrus cultured on modified Murashige and Skoog or Schenk and Hildebrandt media are reported. The bud-forming capacity of the explants depended mainly on the ratios among the levels of ammonium, nitrate, and potassium. The most favorable media formulations for differentiation of adventitious buds were those with nitrate:potassium, ammonium:potassium, and nitrate:ammonium ratios near 1, around 0.1, and between 9 and 15, respectively. The total ionic strength of the media limited bud induction, but only when a disequilibrium of these ratios was produced.