Martínez-Cuenca Mary-Rus, Martínez-Alcántara Belen, Millos Jorge, Legaz Francisco, Quiñones Ana
Department of Citriculture and Vegetal Production, Valencian Institute for Agricultural Research-IVIA, Crta. CV-315, 46113 Moncada, Valencia, Spain.
Service of Food Security and Sustainable Development-C.A.C.T.I., Vigo University, 36310 Vigo, Pontevedra, Spain.
Plants (Basel). 2021 Jan 2;10(1):79. doi: 10.3390/plants10010079.
This work quantifies Fe uptake in young citrus trees, its partitioning among plant compartments, and the contribution of the Fe absorbed from fertilizer to the development of new tissues. A soil pot experiment was conducted using 4-year-old clementine trees ( Hort ex Tan), and a dose of 240 mg Fe was applied by labeled fertilizer (92% atom Fe excess). Plants were uprooted at five different phenologic states: end of flowering (May 15), end of fruit setting and fruit drop (July 1), two fruit growing moments (August 1 and October 15), and at complete fruit maturity (December 10). The Fe accumulated in the root system exceeded 90% of the total Fe content in the plant. All organs progressively enriched with Fe (8.5-15.5% and 7.4-9.9% for young and old organs, respectively). Reproductive ones reached the highest increase (111% between May and October). Fe enrichment from woody organs reflects an increasing gradient to sink organs. The root system accumulated 80% of the Fe absorbed from the fertilizer, but the young organs accumulated relatively more Fe uptake during flowering and fruit setting (15.6% and 13.8%, respectively) than old organs (around 9.8%). Although iron derived from fertilizer (Fedff) preferably supplied young organs (16.7-31.0%) against old ones (2.5-14.9%), it only represented between 13.8% and 21.4% of its content. The use efficiency of the applied Fe (FeUE) barely exceeded 15%. The lowest FeUE were found in young and old organs of the aerial part (1.1-1.8% and 0.7-1.2%, respectively). Since the pattern of the seasonal absorption of Fe is similar to the monthly distribution curve of the supplied Fe, it is recommended that the application of Fe chelates in calcareous soils should be performed in a similar way to that proposed in this curve.
这项研究对幼龄柑橘树中铁的吸收量、在植物各部分间的分配情况以及从肥料中吸收的铁对新组织发育的贡献进行了量化。采用4年生克莱门氏小柑橘树（Hort ex Tan）进行了土壤盆栽试验，通过标记肥料（92%原子过量铁）施加240毫克铁。在五个不同物候期将植株连根拔起：花期结束（5月15日）、坐果结束和落果期（7月1日）、两个果实生长阶段（8月1日和10月15日）以及果实完全成熟时（12月10日）。根系中积累的铁超过植株总铁含量的90%。所有器官中铁含量都逐渐增加（幼嫩器官和成熟器官分别为8.5 - 15.5%和7.4 - 9.9%）。生殖器官增加幅度最大（5月至10月间增加了111%）。木质器官中铁的富集反映出向库器官的梯度增加。根系积累了从肥料中吸收的铁的80%，但幼嫩器官在开花期和坐果期积累的铁吸收量相对较多（分别为15.6%和13.8%），而成熟器官积累量约为9.8%。尽管来自肥料的铁（Fedff）优先供应给幼嫩器官（16.7 - 31.0%）而非成熟器官（2.5 - 14.9%），但其仅占幼嫩器官铁含量的13.8%至21.4%。施用铁的利用效率（FeUE）勉强超过15%。地上部分幼嫩器官和成熟器官的FeUE最低（分别为1.1 - 1.8%和0.7 - 1.2%）。由于铁的季节性吸收模式与供应铁的月度分布曲线相似，建议在石灰性土壤中施用铁螯合物时采用与该曲线类似的方式。
