そ菜のカルシウム吸収に関する研究 (第2報)

Abstract

In many crops, calcium deficiencies in various organs and tissues are often exaggerated due to the low rate of mobility of calcium in plant tissues, and especially under unsuitable conditions for plant growth. Studies were carried out to clarify the influence of naphthaleneacetic acid (NAA) on the mobility of calcium in tomato plants.In the first experiment, tomato seedlings having reached the anthesis stage of the first flower cluster were grown in a nutrient solution with and without calcium, and treated with foliar spray of NAA (10-5M) or CaCl2 (4×10-2M), respectively. The growth of treated plants and the distribution of calcium compounds in leaves of these plants were investigated. In the second experiment: (1) the difference of 45Ca absorption between the plants treated with and without foliar spray of NAA (10-5M) was investigated; (2) immediately after the plants were grown in complete nutrient solution with 45Ca for 4 days, these plants were transferred to a non-45Ca and low calcium nutrient solution with and without foliar sprayed treatment of NAA(-5M), and also held for an additional 21 days. Thereafter, these plants were tested for radioactive analysis and for radioautograms; and (3) 45Ca was applied onto the surface of the leaf and stem, and its subsequent detection on other parts of the plants was made by radioactive analysis.The results are as follows:1. In the plants grown in nutrient solution without calcium, the phenomena of calcium deficiency was found in all clusters and new unfolded leaves of control plants. The same phenomena were found in the third cluster and new unfolded leaves of CaCl2 treated plants. Oppositely, no phenomenon of calcium deficiency was found in NAA treated plants.2. In case of plants which were grown in nutrient solution without calcium and treated with NAA, water soluble fraction calcium in plant tissues apparently increased in the first leaf under the first cluster, and also much more NaCl soluble fraction calcium increased in the first leaf under the second cluster than those in control plants. In the plants treated with CaCl2 only, the higher percentage of all calcium compound was found in leaves than the control plants.3. By the foliar spray treatment with NAA, the treated plants, which were grown in nutrient solution with low calcium level marked with 45Ca, showed a greater amount of radioactivity than plants without NAA treatment.4. Once 45Ca has been deposited in plant tissues, even if a particular migration period be provided, a significant quantity of calcium is not usually transported into new formed tissues. Applying NAA by foliar spray, a very pronounced calcium movement in plant tissues occurred during the 21 day migration period.5. Applying 45Ca with NAA onto the leaf or stem surface, these plants showed a higher amount of 45Ca movement than plants without NAA treatment. But when 45Ca and NAA were treated in different parts of the plant, no effects of NAA on the 45Ca movement were found.