Formation of Adventitious Buds in Stem Internodes of Populus hybrid TT32 Cultured in vitro: Effects of Sucrose, Zeatin, IAA and ABA

Abstract

Internodal explants of poplar 6 mm in length formed adventitious buds when cultured on basal medium. The presence of sucrose was essential and 3% (w/v) was optimal for initiation of buds and their subsequent development into shoots. Explants 2 mm in length were non-morphogenic when cultured on basal medium but produced buds when cultured on medium supplemented with zeatin (0.1 mg/l). IAA and ABA tested at a range of concentrations failed to restore morphogenic capacity to 2 mm explants. The morphogenic response of 6 mm explants was potentiated by low concentrations of zeatin and a five fold increase was obtained with a concentration of 5.0 mg/l. IAA present at high concentration (5.0 mg/l) inhibited formation of adventitious buds in 6 mm explants. Abscisic acid at 1.0 mg/l gave a highly significant inhibition of morphogenic response.