Biofortification and Bioavailability of Rice Grain Zinc as Affected by Different Forms of Foliar Zinc Fertilization

Abstract

BackgroundZinc (Zn) biofortification through foliar Zn application is an attractive strategy to reduce human Zn deficiency. However, little is known about the biofortification efficiency and bioavailability of rice grain from different forms of foliar Zn fertilizers.Methodology/Principal FindingsFour different Zn forms were applied as a foliar treatment among three rice cultivars under field trial. Zinc bioavailability was assessed by in vitro digestion/Caco-2 cell model. Foliar Zn fertilization was an effective agronomic practice to promote grain Zn concentration and Zn bioavailability among three rice cultivars, especially, in case of Zn-amino acid and ZnSO4. On average, Zn-amino acid and ZnSO4 increased Zn concentration in polished rice up to 24.04% and 22.47%, respectively. On average, Zn-amino acid and ZnSO4 increased Zn bioavailability in polished rice up to 68.37% and 64.43%, respectively. The effectiveness of foliar applied Zn-amino acid and ZnSO4 were higher than Zn-EDTA and Zn-Citrate on improvement of Zn concentration, and reduction of phytic acid, as a results higher accumulation of bioavailable Zn in polished rice. Moreover, foliar Zn application could maintain grain yield, the protein and minerals (Fe and Ca) quality of the polished rice.ConclusionsFoliar application of Zn in rice offers a practical and useful approach to improve bioavailable Zn in polished rice. According to current study, Zn-amino acid and ZnSO4 are recommended as excellent foliar Zn forms to ongoing agronomic biofortification.

Biofortification: An Alternative for Zinc and Iron Deficiency in Cereals - A Review.

“…The combined application of Zn as seed priming (2.0%) and foliar spray (2.0%) can improve the performance of maize hybrids (Mohsin et al, 2014). Wei et al, (2012) found that regardless of cultivar, although polishing process decrease substantial amount Zn from mature grain, the polished rice obtained from foliar Zn applications was still contained 10.22-24.04% more Zn than those of control ( Fig. 3) Similar trends were found in polished rice (Fig.…”

Influence of Various Levels of Zinc and Sulphur on Storage Proteins and Protein Quality of Lentil (Lens culinaris) Varieties

“…The application of Sulphur and zinc fertilizers has shown significant effects on yield, uptake of nutrients and quality parameters in diverse crops. Research findings supporting the positive impact of zinc application have been reported earlier in wheat (Mishra, 2012), rice (Zeidan et al, 2010;Wei et al, 2012), maize (Potarzycki et al, 2009), cluster-bean (Meena et al, 2006), chickpea (Burman et al, 2013).…”

Zinc-enriched fertilisers as a potential public health intervention in Africa

“…In addition, those studies that reported milled or polished grain Zn concentrations generally found positive effects of Zn fertilisation. For example, Wei et al (2012) found that foliar application increased Zn concentration in the polished grains of three rice cultivars by 18-28 % and Zhang et al (2012) found significantly greater Zn concentrations in 60-65 % extraction wheat flour (i.e., bran and germ removed) with soil (P<0.05) and foliar (P<0.001) applications of Zn. Despite these findings, when looking across the studies reviewed here, application of Zn via the soil increased concentrations of Zn in brown rice (median=110, Q1= 102, Q3=120 % of control, n=27) but not white rice (median=99, Q1=98, Q3=104 % of control, n=3) and foliar application increased concentrations more in brown (median=130, Q1=114, Q3=147 % of control, n=28) than white (median=117, Q1=112, Q3=122 % of control, n=6) rice.…”

“…The trials combined a range of soil types and cultivars (Table 3; Supplementary Tables 7 and 8). In control plots (i.e., without application of Zn), concentration of Zn in maize grain ranged from 14.9 mg kg −1 DW on calcareous, Zndeficient silty-clay-loam soils in Pakistan (Harris et al 2007) to 22.5 mg kg −1 DW on Zn-deficient sandy-loam in Pakistan (Kanwal et al 2010); concentration of Zn in brown rice (i.e., husk removed but grain unpolished) ranged from 9.9 mg kg −1 DW in Thailand (Phattarakul et al 2012) to 41.6 mg kg −1 DW in 'high-Zn', upland soil in the Philippines (Wissuwa et al 2008); concentration of Zn in polished rice grain ranged from 12.3 mg kg − 1 DW in pH 7.7 soils in Turkey (Phattarakul et al 2012) to 28.0 mg kg −1 DW in Znadequate soils in China (Wei et al 2012); and concentration of Zn in wheat grain ranged from 6.6 mg kg ). The median increases in Zn concentration in the grains of maize, rice and wheat were, respectively, 28, 11 and 18 % for soil application and 30, 24 and 63 % for foliar application (Table 4; Fig.…”

“…2 0 0 8 ; Yang et al 2 0 11 a ; Khoshgoftarmanesh et al 2012;Phattarakul et al 2012;Wei et al 2012;Ghasemi et al 2013;Mabesa et al 2013), suggesting that agronomic and crop breeding biofortification efforts should be aligned. Only one study investigated different cultivars of maize, finding no significant difference between two cultivars (Kanwal et al 2010).…”