Androgenesis in Hexaploid Spring Wheat F2 Populations and Their Parents Using a Multiple-Step Regeneration System

The main goals of the wheat androgenesis experiment were to study the main phenomena of in vitro androgenesis in anther culture of F₂ populations (10) and their parents (6), to compare the usage of P-4 and C-17 media for the formation of embryo/callus and to demonstrate a new plant regeneration system. The P-4 induction medium was found to be significantly better than the C-17 in the number of responsive anthers (RA) and calli induced (CI) at the 1 % and 0.1 % level, respectively. Genotypic effect was evident in both RA and CI. The yields of F₂ populations in RA and CI were significantly higher than those of their parents regarding both media. The data confirmed the existence of heterosis for RA and CI in F₂ populations. The ratio of green/albino plant regeneration was more favourable in the C-17 derived embryo/calli than in the P-4 derived ones. The frequency of plantlet regeneration was enhanced in the group of unresponsive calli by the application of the multiple-step regeneration system. In this system the calli lacking well developed morphogenic structure were transferred to a new regeneration medium, containing a higher concentration of the same cytokinin, other cytokinin or basic medium, before the occurrence of irreversible changes in their physiology.