Cytomorphological and autoradiografical studies on the receptacle of the strawberry (Fragaria grandiflora Eherh.) in the initial stages of development

Abstract

The volume of the cortex and pith cells of strawberries from the cultivar Talizman gradually increased until ripening, especially in the cortex. The volume of the nucleus also increased. The nuclei in the pith were smaller then in the cortex. The volume of the nucleolus increased significantly between days 1 and 5 after pollination, after which it remained unchanged. At the end of the growth period, the volume of the nucleolus in cortical and pith cells in the lower and central part of the fruit increased. Endomitotic polyploidization which was responsible for the growth of the fruit, occurred during the development of the receptacle. The intensity of ³H actinomycin binding reached a maximum in the oldest stages. This is proof for the accumulation of active DNA during mitosis. Saturation with this antibiotic occurred in the early stages of fruit development. No dependence between the volume of cells and the number of nuclei binding ³H actinomycin was observed.