农业环境科学学报2016，Vol.35Issue(4)：613-619,7.DOI:10.11654/jaes.2016.04.001
UV-B辐射对元阳梯田水稻根系LMWOAs分泌量和根际微生物数量的影响
Effects of UV-B radiation on rice roots-exudated LMWOAs and rhizospheric microorganism quantities in a paddy field of Yuanyang Terraces, Yunnan Province
摘要
Abstract
A local rice variety,“Baijiaolaojing”, was grown in a paddy field in the Yuanyang Terrace under ambient and elevated(5.0 and 10.0 kJ·m-2)ultraviolet-B(UV-B, 280~315 nm)radiation. The rice plant and rhizospheric soil were sampled at jointing-booting, heading-flowering and maturity stages of rice. The exudation of low-molecular-weight organic acids(LMWOAs)including oxalic acid, succinic acid, tartaric acid, and malic acid by rice roots and the quantity of 7 microbial groups in rice rhizosphere were determined. Results showed that elevated UV-B radiation increased the concentrations of oxalic acid and succinic acid, but decreased tartaric acid and malic acid. Rhizo-spheric bacteria, fungi, azotobacteria, cellulose-decomposing bacteria, inorganic phosphobacteria and potassium bacteria were found to be the highest at the maturity stage, the next at the jointing-booting stage, and the lowest at the heading-flowering stage. The maximum rhizo-spheric actinomycetes was observed at the jointing-booting stage, the second at the heading-flowering stage, and the lowest at the maturity stage. Elevated UV-B radiation didn′t alter the dynamics of rice rhizospheric microorganism quantities along with the rice growth stages, but induced a significant or very significant increase in the quantities of the 7 microbial groups in the rice rhizosphere. Significant positive cor-relations were found between oxalic acid exudation and the quantities of rhizospheric azotobacteria and cellulose-decomposing bacteria, be-tween succinic acid and azotobacteria;and very significant positive correlations between succinic acid exudation and the quantity of bacteri-a, fungi, cellulose-decomposing bacteria, inorganic phosphobacteria and potassium bacteria. These findings indicate that elevated UV-B ra-diation influences rhizospheric microorganism quantity rice under field, which is closely associated with LMWOAs exudation by rice roots.关键词
UV-B辐射增强/元阳梯田/水稻根际/低分子量有机酸/微生物数量Key words
elevated UV-B radiation/Yuanyang Terrace/rice rhizosphere/low-molecular-weight organic acids/microbial quantity分类
资源环境引用本文复制引用
何永美,湛方栋,吴炯,高召华,李元..UV-B辐射对元阳梯田水稻根系LMWOAs分泌量和根际微生物数量的影响[J].农业环境科学学报,2016,35(4):613-619,7.基金项目
国家自然科学基金项目 （）
