摘要：The purpose of the research was to study the behavior of several Acer varieties : Acer p a lmatum 'Dissectum Atropurpureum' and Ace r platanoides 'Crimson King', 'Drummondii' an d 'Globosum' , during the first subculture of the i n vitro multiplication phase . There were used explants from the initiation phase and passed on the multiplication nutrient media. The nutri ent media tested were MS, DKW and WPM and each had a different cont ent of growth hormones. In order to determine the multiplication rate, w as tested the influence of zeatin and thidiazuron, in concentration of 1. 5 mg/l , on a constant level of indol e - butyric acid (0. 5 mg/l ). In the growing chamber were a constant temperatu re and a photoperiod of 14 hours light/ 24 hours, at a luminosi ty of 2 500 lux . From the observations and registered data w as determined the multiplication rate (microshoots/explant) for the four genotypes
