Liu Dun-Yi, Liu Yu-Min, Zhang Wei, Chen Xin-Ping, Zou Chun-Qin
Key Laboratory of Plant-Soil Interactions, Ministry of Education, Center for Resources, Environment and Food Security, China Agricultural University, Beijing, China.
Chongqing Key Laboratory of Efficient Utilization of Soil and Fertilizer Resources, College of Resources and Environment, Southwest University, Chongqing, China.
Front Plant Sci. 2019 Apr 16;10:426. doi: 10.3389/fpls.2019.00426. eCollection 2019.
Effect of zinc (Zn) application to soil on root growth and Zn uptake and translocation in winter wheat are poorly understood. This study evaluated the effect of soil Zn fertilization (0, 2.3, 5.7, 11.4, 22.7, 34.1 kg of Zn ha) on root growth and distribution, crop Zn uptake, root-to-shoot translocation of Zn, and remobilization of Zn from shoot to grain. Results of this study revealed that Zn application ≤11.4 kg ha significantly increased root dry weight, root length density, and root surface area within 0-30 cm soil depth and higher rates of Zn application caused slight decreases in these root parameters. Shoot biomass and shoot Zn accumulation increased as Zn application rate increased mainly because of improved matching of root growth and enhanced availability of Zn in the topsoil layer. Post-anthesis Zn uptake by shoot increased and translocation of Zn from root to shoot decreased as rate of Zn application increased. The degree to which Zn accumulation in grain resulted from pre-anthesis remobilization vs. post-anthesis shoot uptake depended on Zn availability in soil; post-anthesis shoot uptake dominated at DTPA-Zn concentrations >7.15 mg kg, and pre-anthesis remobilization dominated at lower soil Zn levels. In conclusion, Zn uptake, translocation and remobilization to grain were affected by root growth and its matching with the availability of soil Zn. The results suggest that soils similar to the study soil should be fertilized to 30 cm depth with about 11.4 kg ha Zn in order to obtain high yield and grain Zn concentration of wheat.
土壤施锌（Zn）对冬小麦根系生长、锌吸收及转运的影响尚不清楚。本研究评估了土壤施锌量（0、2.3、5.7、11.4、22.7、34.1 kg Zn/ha）对根系生长与分布、作物锌吸收、锌从根到地上部的转运以及锌从地上部向籽粒的再转运的影响。本研究结果表明，施锌量≤11.4 kg/ha显著增加了0-30 cm土壤深度内的根干重、根长密度和根表面积，而较高施锌量导致这些根系参数略有下降。地上部生物量和地上部锌积累量随施锌量增加而增加，这主要是由于根系生长的改善以及表层土壤中锌有效性的提高。随着施锌量增加，花后地上部对锌的吸收增加，锌从根到地上部的转运减少。籽粒中锌积累量由花前再转运与花后地上部吸收所贡献的程度取决于土壤中锌的有效性；在DTPA-Zn浓度>7.15 mg/kg时，花后地上部吸收起主导作用，而在土壤锌水平较低时，花前再转运起主导作用。总之，锌向籽粒的吸收、转运和再转运受根系生长及其与土壤锌有效性匹配的影响。结果表明，与本研究土壤类似的土壤应以约11.4 kg/ha的锌施用到30 cm深度，以获得小麦的高产和籽粒锌浓度。
