Plant hormones play important roles in the regulation of flower development. To study hormone-regulated inflorescence development, we established two different in vitro regeneration systems of Arabidopsis inflorescences in the presence of cytokinin and auxin. The inflorescence stems of wild type Arabidopsis (Ecotype Wassilewskija) were excised into 2~3 mm lengths as explants when the first flowers of the plants were at anthesis. In the first regeneration system, media containing a combination o...