Seed dormancy and germination in Jeffersonia dubia (Berberidaceae) as affected by temperature and gibberellic acid.

摘要: The genus Jeffersonia, which contains only two species, has a trans-Atlantic disjunct distribution. aims of this study were to determine the requirements for breaking dormancy and germination J. dubia seeds compare its characteristics with those congener in eastern North America. Ripe contain an underdeveloped embryo permeable water. In nature, dispersed May, while embryos began grow September, fully elongated by late November. Germination started March next year, emerged as seedlings soon after germination. laboratory experiments, incubation at high temperatures (25 °C, 25/15 °C) least 8 weeks was required initiate growth, transfer moderate (20/10 15/6 needed completion growth. At 5 °C effective overcoming physiological had elongated. Thus, both low essential break dormancy. Gibberellic acid (GA3) treatment could substitute temperature requirement, but not requirement. Based on dormancybreaking requirements, it is confirmed that have deep simple morphophysiological This type similar American species diphylla. Although require 10–11 months from seed dispersal under controlled conditions they