Morphological aspects of apple seedling early development in relation to embryonal dormancy

The growth of root, hypocotyl and cotyledons was measured in apple seedlings cultured for nine days from embryos isolated from seeds after various periods of after-ripening. Greening of the cotyledons was taken into account and the chlorophyll content determined as well. Embryonal dormancy results in anomalies already appearing in the early stage of development. They are manifested by differentiated greening and uneven growth of cotyledons, as well as by hypotrophy of root or hypocotyl. The frequency of those anomalies in the population decreases during the removal of dormancy, and therefore it may be accepted as the criterion of its depth.