The seasonal changes in endogenous levels of indole-3-acetic acid, gibberellic acid, zeatin and abscisic acid in stems of some apple varieties (Malus sylvestris Miller)
Seasonal changes of total indole-3-acetic acid (IAA), gibberellic acid (GA3), zeatin and abscisic acid (ABA) levels were investigated in stem cuttings of apple (Malus sylvestris Miller) varieties, Golden delicious, Starkrimson delicious and Misket delicious' at different times of the year. All of the apple varieties exhibited seasonal differences in hormone levels. The total IAA, GA3 and zeatin contents of these apple varieties increased to the highest value in May but it was the lowest in February. Whereas ABA levels observed in May were lower in the studied apple varieties, but it was the highest level in February. Except for ABA other hormones, IAA, GA3 and zeatin levels, were the lowest in 'Misket delicious' among the all apple varieties in all sampling periods (August-May). © 2008 Asian Network for Scientific Information.