Employ the Colored Rice Cultivars Under the Foliar Biofortification to Facilitate the Zinc Enrichment

It is difficult for ordinary rice to break the zinc-rich standard. However, employing multiple unique rice cultivar resources through biofortification of agronomic measures to achieve this target is a novel attempt that has rarely been reported. In this study, the effects of foliar application of water-soluble zinc-rich fertilizer (400 g/ha Zn) on seven different cultivars (GFHN 166, GFHN168, GFHN 169, GH 1, GXHZ, GHSZ and YXN) of colored rice at heading stage were investigated through pot experiment. The result indicated that foliar biofortification significantly increased the zinc content of colored rice grains by 43.89%, and the zinc accumulation in grains increased by 64.50%. In addition, the SPAD value and grain protein content also increased significantly by 2.15% and 2.86%, respectively. Among these, GXHZ and GHSZ could realize the zinc content of polished rice up to 69.7 mg/kg and 55.4mg/kg, breaking through the standard of zinc-enrich rice (45mg/kg). GXHZ plant height increased by 11.22%, and the zinc harvest index (6.44%) and zinc use efficiency (26.79%) were the highest. Meanwhile, the biofortification promoted the SPAD value of GHSZ and the protein content of GFHN 166 by 4.95% and 24.81%, respectively. And zinc-treated colored rice at the concentration used in this study has no risk to human health. Combining the foliar application of exogenous zinc with the utilization of specific cultivars resources could realize zinc-enrich rice production, and provide an additional resolution for tackling the hidden hunger problems.