The influence of cytokinin pulse treatments on adventitious bud formation on vegetative buds of Picea abies

Abstract

Resting vegetative buds of Picea abies collected from phytotron-grown rooted cuttings of 24-year-old trees or a 12-year-old hedge were tested for their capacity to form adventitious buds after various cytokinin treatments. The most effective method for obtaining a high yield of adventitious buds within 8 weeks was to pulse treat the buds in 250/~M BA for 3 h and then culture them on medium containing 5 #M each of BA and kinetin for 1 week. The developmental pattern for adventitious bud production, with the formation of 10 to 20 adventitious buds per bud, was similar for all tested genotypes, although the number of buds giving rise to adventitious buds varied significantly. The capability of some clones to form adventitious buds was correlated to endogenous cytokinin content. The clone which contained most endogenous cytokinin in its resting bud had the highest potential for adventitious bud formation.

Axillary shoot proliferation in cultures of explants from mature Juniperus oxycedrus trees

“…There was also a progressive loss of morphogenetic potential and an increase in hyperhydricity of the explants with increasing exposure to BA. However, pulse treatments of cytokinins have improved caulogenesis in other conifers (Bornman 1983, von Arnold and Tillberg 1987, Jang and Tainter 1991.…”

The relationship between genotype, tissue age and endogenous cytokinin levels on adventitious bud formation on leaves of Lachenalia

“…The gradient in regeneration potential which exists within an organ as a result of different developmental stages [11,17] can be cited as an exampie. Furthermore, the differential responses of species or cultivars to culture conditions have been attributed to different levels of endogenous hormones within different genotypes [4,16].…”

Simplified protocol for the micropropagation of selected Eucalyptus and Banksia species

“…It would appear that in callus cultures there was considerable benefit in pulsing the culture material with high concentrations of BA to induce large numbers of shoot primordia, then lowering the BA concentration in subsequent subcultures to promote shoot elongation. Cytokinin pulsing has been used successfully by Von Arnold and Tilberg (1987) on micro-cuttings of Picea abies to increase the yield and quality of cuttings.…”