Growth, development and respiration in the ovules of Zephyranthes lancasteri at different stages of maturation

Abstract

Changes in the rate of respiration and activity of succinic dehydrogenase in the ovules, embryo and endosperm have been investigated at different stages of seed development in Z. lancasteri. An attempt has been made to find any possible relation between physiological changes and the growth pattern of ovule. The fertilized ovules mature into seeds in 16–19 days from the time of pollination. The respiratory course and the growth of ovules follow identical trends. The curve for oxygen uptake is characterized by at least two peaks; the first on the sixth or seventh day is related to the laying down of walls in the coenocytic micropylar chamber of the endosperm and the second on the 11th day precedes the elongation of cotyledon. In excised endosperm the activity of succinic dehydrogenase is highest during its transformation from freenuclear to cellular state, while in the embryo it is so after the attainment of mature size.