Abstract

To determine arsenic (As) phytotoxicity in gramineae, a hydroponic experiment with oat was conducted. Twenty-four days old oat seedlings were treated with sodium meta-arsenite (NaAsO₂) for 14 days at different rates of As in the greenhouse. Shoot growth decreased by 28.17, 38.34, 68.34, and 75.85%, while the root growth decreased by 33.51, 42.61, 64.79, and 72.15% for 6.7, 13.4, 26.8, and 53.6 µM As treatments, respectively, indicating that the roots were more sensitive to As-toxicity than that of shoots. Arsenic at the rate of 13.4 µM level produced chlorotic symptom in the 4th leaf. Necrotic symptom was found in the old leaves at 26.8 and 53.6 µM As levels. Arsenic concentration increased both in shoots and roots with the increasing As concentration in the solution. Mostly, the concentrations of P, Fe, and Zn decreased in shoots. On the contrary, As and Fe concentrations increased in roots with the increasing As concentration in the solution. The research suggested that As hindered Fe translocation from roots to the shoots, resulting in whitish chlorotic symptom in the leaves.

摘要

为了确定禾本科植物中砷 (As) 的植物毒性，进行了燕麦水培实验。用偏亚砷酸钠 (NaAsO ₂) 14 天在温室中不同的砷含量。6.7、13.4、26.8和53.6的地上部生长分别降低了28.17、38.34、68.34和75.85%，而根生长分别降低了33.51、42.61、64.79和72.15%，表明根系更多对 As 毒性比对芽更敏感。13.4 µM 水平的砷在第 4 片叶子中产生褪绿症状。在 26.8 和 53.6 µM 砷水平下，在老叶中发现了坏死症状。随着溶液中砷浓度的增加，地上部和根中的砷浓度均增加。大多数情况下，枝条中 P、Fe 和 Zn 的浓度降低。相反，根中的 As 和 Fe 浓度随着溶液中 As 浓度的增加而增加。研究表明 As 阻碍了 Fe 从根向芽的易位，