Soil and Environmental Sciences Division, Nuclear Institute for Agriculture and Biology (NIAB), Faisalabad, Pakistan.
J Sci Food Agric. 2018 Aug;98(11):4351-4356. doi: 10.1002/jsfa.8961. Epub 2018 Mar 25.
The negative effect of soil-applied phosphorus (P) on zinc (Zn) uptake by plants and its concentration in food grains could be a possible reason for low dietary intake of Zn. Likewise, owing to its critical role in plant tolerance to other abiotic stresses, potassium (K) was thought to retrieve P-induced decrease in grain Zn concentration of wheat. To test the above hypothesis, the effect of K application (50 mg kg soil) on Zn concentration in shoot/grains and its shoot-to-grain translocation was studied in wheat (Triticum aestivum L. cv. Galaxy-2013) under low and optimal supply of both P (10 and 50 mg kg ) and Zn (0 and 5 mg kg ).
The response of growth parameters and grain yield to optimal Zn, P and K applications indicated that all nutrients were limiting plant growth at low levels. Irrespective of P level, Zn application at optimal rate increased Zn concentration and uptake by straw and grains of wheat. Contrarily, optimal P application decreased Zn concentration but increased Zn uptake by wheat straw. More specifically, combined application of Zn and P at optimal levels decreased Zn concentration in grains from 43 to 32 mg kg compared with optimal Zn application alone. Potassium application to optimal P- and Zn-supplied plants increased remobilization of pre-anthesis straw Zn store to grains by 50% and decreased Zn concentration in straw. Consequently, K application along with optimal Zn and P supply to plants completely retrieved P-induced loss in grain Zn concentration and also increased grain Zn uptake from 891 to 1249 µg per pot without significantly affecting grain yield.
The K-induced increase in grain Zn concentration is attributed to K-driven higher post-anthesis Zn uptake and remobilization of pre-anthesis straw Zn store to grains. © 2018 Society of Chemical Industry.
土壤施磷（P）对植物锌（Zn）吸收及其在粮食中的浓度的负面影响可能是导致膳食 Zn 摄入量低的一个原因。同样，由于钾（K）在植物耐受其他非生物胁迫方面的关键作用，人们认为 K 可以弥补 P 降低小麦籽粒 Zn 浓度的作用。为了验证上述假设，本研究在低磷（P）（10 和 50 mg kg）和锌（Zn）（0 和 5 mg kg）供应条件下，研究了 K （50 mg kg 土壤）对小麦（Triticum aestivum L. cv. Galaxy-2013）地上部/籽粒 Zn 浓度及其向籽粒转移的影响。
最佳 Zn、P 和 K 处理对生长参数和籽粒产量的响应表明，所有养分在低水平下均限制了植物的生长。无论 P 水平如何，在最佳浓度下施用 Zn 均增加了小麦秸秆和籽粒的 Zn 浓度和吸收。相反，最佳 P 处理降低了 Zn 浓度，但增加了小麦秸秆的 Zn 吸收。具体来说，与单独最佳 Zn 处理相比，最佳 Zn 和 P 处理降低了籽粒中 Zn 浓度从 43 至 32 mg kg。K 处理最佳 P 和 Zn 供应的植株，使前茬秸秆 Zn 库在开花后向籽粒的再转移增加了 50%，并降低了秸秆中的 Zn 浓度。因此，在不显著影响籽粒产量的情况下，K 与最佳 Zn 和 P 一起施用于植株可完全弥补 P 诱导的籽粒 Zn 浓度损失，并将籽粒 Zn 吸收量从 891 增加至 1249 µg 每盆。
K 诱导的籽粒 Zn 浓度增加归因于 K 驱动的开花后 Zn 吸收增加和前茬秸秆 Zn 库向籽粒的再转移。 © 2018 英国化学学会。
