文献类型： 外文期刊

作者： Ding, Y. ¹ ; Luo, W. ² ; Xu, G. ² ;

作者机构： 1.Nanjing Agr Univ, State Key Lab Crop Genet & Germplasm Enhancement, Coll Resources & Environm Sci, Nanjing 210095, Peoples R China

2.Nanjing Agr Univ, State Key Lab Crop Genet & Germplasm Enhancement, Coll Resources & Environm Sci, Nanjing 210095, Peoples R China; Shanxi Acad Agr Sci, Inst Soil & Fertilizer, Taiyuan, Peoples R China

关键词： magnesium;nutritional interaction;Oryza sativa L.;potassium

期刊名称：ANNALS OF APPLIED BIOLOGY （ 影响因子：2.75； 五年影响因子：2.942 ）

ISSN： 0003-4746

年卷期： 2006 年 149 卷 2 期

页码：

收录情况： SCI

摘要： Magnesium (Mg) is known as one of the essential nutrients for higher plants; yet, the preliminary physiological responses of field crops to its deficiency or excess, particularly to its interaction with potassium (K), remain largely unknown. In this study, we observed that Mg deficiency in rice (Oryza sativa) [less than 1.1 mg g(-1) dry weight (DW) in the shoot] resulted in significant reduction in shoot biomass, decrease in total chlorophyll concentration and net photosynthetic rate and reduction in activities of both nitrate reductase [NR; enzyme classification (EC) 1.6.6.1] and glutamine synthetase (EC 6.3.1.2) in the leaves. However, the Mg-deficient plant contained higher starch in the leaves, and partitioned larger biomass into roots. Excess of Mg (more than 3.0 mg g(-1) DW in the shoot), together with low K supply, suppressed NR activity and decreased concentration of soluble sugar in the leaves. There were great antagonistic and moderately synergistic effects between K and Mg, but the effects of K were much more significant than those of Mg on their uptake and translocation, NR activity and net photosynthetic rate in the leaves. The optimum weight ratio of K to Mg ranged between 22 and 25 in the leaves at tillering stage. Mg deficiency was not compensated for by moderate supply of K but was aggravated by excess supply of K, suggesting specific roles of Mg in both dry matter production and partition of carbon assimilates in rice.