Cesium uptake and translocation from tea cutting roots (Camellia sinensis L.).

To estimate the uptake of radiocesium (Cs) by tea plant roots, 1-year-old rooted tea cuttings (Camellia sinensis L. cv. Yabukita) at the time of bud opening were cultivated hydroponically for 27 days in pots containing nutrient solutions with or without CsCl (600 Bq mL). Total Cs radioactivity of whole tea plants were 6.1 kBq g dry weight. The plant/solution Cs transfer factors of different tissues were in the range of 2.6 (in mature leaves) to 28.2 mL g dry weight (in roots), which were lower than those reported in wheat and spinach. In total, 69% of Cs remained in roots and 31% was transported from roots to shoots. The results indicated that Cs was preferentially translocated to new shoots, which are used for manufacturing tea, over mature leaves.