The use of an in vitro adventitious bud technique for mutation breeding of Begonia x hiemalis

An in vitro propagation of two genotypes of Begonia x hiemalis was achieved through adventitious shoot formation on (sub) cultured leaf-disc explants and subsequent transplantation to soil of explant-parts with adventitious shoots. After irradiation of detached leaves with different doses of X-rays and two cycles of adventitious shoot formation on in vitro (sub) cultured leaf-disc explants, plantlets were produced. About 30% of these plants was mutated with respect to e.g. the colour, size and form of the leaves and flowers. The great majority of the mutants (98.5%) proved to be solid (non-chimeric). (orig.)