| Popis: |
Movement of Cs137 was followed from floral parts of inoculated trees, through seed maturation, and into components of germinated seedlings of yellow poplar (Liriodendron tulipifera L.). Radiocesium concentrations and dry weight in fruit increased during the growing season until early fall, then decreased slightly. During the first 3 weeks of growth, the cotyledons of germinated seedlings lost about half of their Cs137 content to other rapidly growing tissues. During the next 4 weeks, additional radiocesium was translocated into new leaf growth while stem and root levels tended to remain relatively stable. From the seventh to the tenth week of growth, a large influx into roots occurred, and other plant components exhibited a decrease in radiocesium. The data indicated that Cs137, in both fruit and seedlings (e.g., cotyledons), followed pathways paralleling those of sugars and other translocated organic substances which may be stored in tissues later used to sustain early seedling growth. In addition, the s... |
