Micropropagation of European Birch (Betula pendula Roth.), Paper Birch (B. papyrifera Marsh.) and Yellow Birch (B. lutea Michx.)

1991

S. 23-31

3 Abb., 3 Tab., 17 Lit. Ang.

Unselbständiges Werk

200041910

The vegetative propagation by conventional methods which exploit natural mechanisms of asexual reproduction, rooting of cuttings and grafting, is time consuming and of limited success for many tree species. Tissue culture techniques offer a new dimension to tree improvement and may serve as an adjunct to conventional tree-breeding programs. In present paper we described how micropropagation technique could be used in production and genotypes selection of three birch species Betula pendula, B. papyrifera and B. lutea. Initial explants - axillary bud meristems, were excised from two-, four- and twenty-year-old European birch, as well as from two-year-old paper and yellow birch. The branches were collected in winter to early spring before foliation. The modified aspen culture medium (ACM) with low concentration of cytokinin BA was used as initial medium for shoot induction and multiplication. The differences observed in all micropropagation stages were affected by different morphogenetical capacity of tested species as well as their genotypes. Multiplication rate achieved was 4-6 nodal segments per explant. The adventitious root system was developed on the basal portion of shoots on the same medium composition (mod. ACM) supplemented with 1.0 uM IBA. Plantlets which passed through hardening period, were developed into the normal plants in field conditions. The results presented in this paper showed, also, that our micropropagation method could be used for propagation of mature birch trees.