Proliferation and rooting of wild cherry : the influ ence of cytokinin and auxin types and their concentration

Abstract

Determination of the most optimal type and concentr ation of plant growth regulators as medium constituents is one of the most important aspects o f successful micro propagation, among other in vitro factors. With the aim of optimization of in vitro multiplication of wild cherry, the effect of the following cytokinins was studied: 6-benzyladenine (B AP), 2-isopentenyl adenine (2iP) and kinetin (Kin) at concentrations of 1, 2, 4 and 8 mg. l -1 . Stem segments of seedlings from juvenile and adul t materials were disinfected and grown on a Quoirin and Lepoivr e (1977) (QL) medium without growth regulators for 4 weeks. Each material responded differently to the tested cytokinins. The use of 6-benzyladenine resulted in the highest percentage of sprouting, th e development of shoots and the ratios of multiplication for two materials of Prunus avium L. In the next experiment, seedlings from the juve nile and adult materials were grown on (MS2/5) medium in the presence of auxins indole-3-butyric acid (IBA), naphtaleneacetic acid (NAA), indole-3-acetic acid (IAA), when compared with concentrations of 0.5, 1, 2, and 4 mg. l -1 . For the type of explants and its reactivity with the type and the concentration of auxin, significant differences among explants for r oot induction were observed. The adult material did not develop roots in any of the auxin and concentra tion used. In the case of the juvenile material, th e IBA was distinguished from the other auxins tested and the highest induction of roots took place in 1 mg. l -1 . The most significant induction of cal characterize s, especially, the mediums containing the NAA followed by the IAA with concentrations of 2 and 4 mg. l -1 , respectively, which block the emergence of the roots partly and decreases the rate of rooting thereafter. The highest average number of roots and the highest average length of roots were obtained w ith the IBA with 1 mg. l