Pedosphere 10(4): 333--338, 2000
ISSN 1002-0160/CN 32-1315/P
©2000 Soil Science Society of China
Published by Elsevier B.V. and Science Press
| Effect of soil moisture on release of low-molecular-weight organic acids in root exudates and the accumulation of iron in root apoplasm of peanut |
| ZHENG Yi and ZHANG Fu-Suo |
| Department of Plant Nutrition, China Agricultural University, Beijing, 100094 (China) |
| ABSTRACT |
| A three-compartments rhizobox was designed and used to study the low-molecular-weight organic acids in root exudates and the root apoplastic iron of "lime-induced chlorosis" peanut grown on a calcareous soil in relation to different soil moisture conditions. Results showed that chlorosis of peanuts developed under condition of high soil moisture level (250 g kg-1), while peanuts grew well and chlorosis did not develop when soil moisture was managed to a normal level (150 g kg-1). The malic acid, maleic acid and succinic acid contents of chlorotic peanut increased by 108.723, 0.029 and 22.446 μg cm-2, respectively, compared with healthy peanuts. The content of citric acid and fumaric acid also increased in root exudates of chlorotic peanuts. On Days 28 and 42 of peanut growth, the accumulation of root apoplastic iron in chlorotic peanuts was higher than that of healthy peanuts. From Day 28 to Day 42, the mobilization percentages of chlorotic peanuts and healthy peanuts to root apoplastic iron were almost the same, being 52.4% and 52.8%, respectively, indicating that the chlorosis might be caused by the inactivation of iron within peanut plant grown on a calcareous soil under high soil moisture conditions. |
| Key Words: apoplastic iron, peanut, root exudates, soil moisture |
| Citation: Zheng, Y. and Zhang, F. S. 2000. Effect of soil moisture on release of low-molecular-weight organic acids in root exudates and the accumulation of iron in root apoplasm of peanut. Pedosphere. 10(4): 333-338. |
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