Adventitious shoot formation on excised hypocotyls of Antirrhinum majus L. (snapdragon) in vitro

摘要

Hypocotyls from Antirrhinum majus were excised at 2 weeks of age from seedlings grown under a 16-h photoperiod or continuous darkness. Explants were cultured on modified Murashige-Skoog (MS) medium containing 0, 0.44, 2.22, 4.44, 8.88 or 44.4μM benzyladenine (BA) to investigate adventitious shoot formation. Excised hypocotyls from 8 commercial cultivars, 3 inbred lines and an F1 hybrid between 2 of the inbreds were cultured on MS medium containing 2.22μM BA to assess genotypic effects on adventitious shoot formation. The influence of seedling age was assessed by excising hypocotyls from seedlings at 6, 10, 14, 18, 22, 26 or 30 days. Optimal conditions for adventitious shoot formation on excised hypocotyls included: seedling growth in a lighted environment, use of hypocotyls from 10-day-old seedlings, and culture on medium containing 2.22μM BA for 3 weeks. Under these conditions, up to a 5-fold improvement in number of shoots per hypocotyl over previous studies was achieved. Adventitious shootformation was genotype-dependent and appeared to be a dominant trait.