A Histochemical and Ultrastructural Study of Pre- and Post-Germinated Yucca Seeds

Ungerminated and post-germinated seeds of four species of Yucca were studied at the light and electron microscope levels to determine the general chemical nature of the reserve constituents and how these constituents are utilized during seedling growth and development. Embryo and seed nutritive tissues contain many oil and protein bodies. The nutritive tissue cell walls are thick and contain many pit regions. During germination and post-germination stages, these three reserve constituents (oil, protein, and carbohydrate) are degraded and utilized. This study also follows the changes which occur in the buildup and depletion of RNA and starch within the seed. Correlations are made between the results of histochemical procedures at the light microscope level and ultrastructure observations.