植物营养与肥料学报Issue(5)：1286-1293,8.DOI:10.11674/zwyf.2015.0523
外源S2-抑制水稻生长及土壤微生物活性的半效应浓度研究
EC50 of soil S2-inhibiting rice growth and soil microbial activities
摘要
Abstract
[Objectives]S2- is one of the important limiting factors for rice growth in cold waterlogged paddy fields which are typical low yield paddy fields. Characteristics of ecological toxicity of S2-to system of soil-rice under S2-stress were investigated in order to provide a theoretical basis for future research to reveal the dose critical value of S2- toxicity and its toxic mechanism in cold waterlogged paddy soil. [Methods] Effect of exogenous S2- treatment on rice physiological indices ( rice physiological growth, chlorophyll, proline and the activities of the antioxidant enzyme system in the rice leaves) , soil microbial activities and their bioecological characters at the seedling and tillering stages in the interactive system of soil-rice-S2- and microbe were studied by a greenhouse pot experiment which is set to simulate S2- toxicity in waterlogged paddy soil. A single season conventional late japonica rice Xiushui 134 was selected as crop material, and S2-was applied at seven different levels in one paddy soil, namely 0, 10, 50, 100,300, 600 and 1200 mg/kg. [Results] The addition of exogenous S2-gradually inhibits the growth of rice and decreases soil microbial activities in the normal tested paddy soil in which the background S2-concentration is 12. 08 mg/kg. The plant height and dry matter accumulation of rice decrease sharply when the exogenous S2-concentration exceeds 50 mg/kg. However, SPAD value of chlorophyll content in rice leaves, proline accumulation and activities of antioxidant enzyme systems are increased significantly. These results suggest that exogenous S2-of 50 mg/kg is the critical concentration under the tested condition to poison rice growth. Meanwhile, soil microbial activities are declined rapidly with the increase of the concentration of exogenous S2-. The turning point of decreasing soil microbial activities can be presumed as 40 mg/kg of soil S2- concentration by analyzing its toxicant concentration that inhibits a microbe-mediated ecological process by 50%( EC50 ) . Soil microbial activities and rice growth in the system of soil-rice-S2-and microbe are significantly associated and synchronously affected by S2- in the tested soil. Overall, soil S2-of 40 mg/kg is the critical concentration to inhibit the system of soil-rice-soil microbe in the tested soil. [Conclusion] When the concentration of S2-in soil exceeds a certain concentration, S2-would lead to significantly negative effects on the system of soil-rice-soil microbe. Soil S2- of 40 mg/kg is the critical concentration to inhibit the system of soil-rice-soil microbe in the tested soil. Therefore, some reasonable agronomic measures should be taken to control the negative effects once the concentration of S2-is over 40 mg/kg in the test paddy soil.关键词
硫离子/水稻生理指标/土壤微生物量/土壤微生物活性Key words
sulfur ion/rice physiological indices/soil microbial biomass/soil microbial activities分类
农业科技引用本文复制引用
谢晓梅,廖敏,张楠,徐培智,徐昌旭,刘光荣..外源S2-抑制水稻生长及土壤微生物活性的半效应浓度研究[J].植物营养与肥料学报,2015,(5):1286-1293,8.基金项目
国家公益性行业(农业)专项(201003059)资助。 （农业）
