FACTORS CONTROLLING MICROPROPAGATION OF MATURE FAGUS-SYLVATICA

The influence of several endogenous factors on micropropagation of mat ure elite trees of beech (Fagus sylvatica L.) has been investigated. F ebruary was the most beneficial month for explantation of dormant buds , since infection with endogenous bacteria was still low and in vitro growth of the plant material was the highest. The genotypes tested gav e different results concerning their growth on various tissue culture media. Out of 51 mature grafted genotypes only seven could be establis hed in vitro. Grafting of branches of mature stock plants on juvenile rootstocks resulted in a high increase of multiplication rate compared with corresponding mature material, which could not be subcultured in vitro. Apical buds, larger than 20 mm, from 1-year-old shoots proved to be the most suitable explant source. Plant material could be subcul tured for several years and rooted successfully.