Effects of source of macronutrients and plant growth regulator concentrations on shoot proliferation of Cornus florida

Nodal stem segments of flowering dogwood (Cornus florida L.) were cultured on media containing seven different sources of macronutrients including full- and half-strength Murashige & Skoog (MS) macrosalts, N6, Anderson's (AND), Quoirin & Lepoivre's (LP), Nitsch & Nitsch (NIT), and Woody Plant Medium (WPM). All media contained MS micronutrients, Staba vitamins, 20 g l^-1 sucrose, and 6.5 g l^-1 Difco Bacto-agar, and were supplemented with 2.2 μM 6-benzyladenine (BA) and 0.49 μM indole-3-butyric acid (IBA). Following three subcultures, the best shoot proliferation was supported on media containing WPM macronutrients. To optimize the proliferation rate, shoots were cultured on WPM macronutrients supplemented with eight combinations of BA and IBA, and 3.3 μM BA without IBA was determined to be the best.