Micropropagation of Hagenia abyssinica: a multipurpose tree

Abstract

An in vitro propagation protocol has been developed for Hagenia abyssinica using original material from both juvenile and mature trees. Juvenile explants were obtained from seedlings, as well as shoots and meristems from 5 to 7-month-old greenhouse grown plants. Shoots collected from stem bases of five genotypes were used to establish cultures from mature trees. Explants of seedling origin were used to optimize the multiplication medium and growth regulators concentration. The best result was obtained from shoots subcultured on either MS or WPM medium supplemented with 4.4 μM BAP and 0.49 μM IBA. The initiated shoots from all the different explants were multiplied on these media. Rooting of shoots was achieved using MS medium containing macronutrients at one-third strength supplemented with 4.9 μM IBA. The shoots were kept in the dark for 4 days and transferred to medium of the same composition but containing 0.3% activated charcoal without growth regulators. Up to 100% rooting was achieved depending on genotype. Shoots multiplied on MS medium rooted better than those multiplied on WPM. Plantlets were transferred to pots containing a mixture of soil and perlite in a 2:1 ratio, respectively, and were maintained in the greenhouse. Increased irradiance reduced stem and leaf lengths and increased branch number of micropropagated plants.