Effect Of Foliar Application Of Zinc Fertilizer On Zinc Uptake, Partitioning And Accumulation In Rice

Zinc is not only the necessary micronutrient element to humans, but also one of the three most easily absent microelement Zn, Fe, VA.Generally, the regions in the world with Zn-deficient cereals are also characterized by widespread Zn deficiency in humans. Agronomic biofortification would be a very attractive and useful strategy in solving Zn deficiency-related health problems globally and effectively. However, the mechanism of the uptake, accumulation and partitioning of microelement by rice is poorly documented both at home and abroad. In this thesis, field and pot experiment were conducted on rice to evaluate the effect of Zn and Fe foliar fertilization on the concentration of these micronutrients, yield, quality and zinc-iron partitioning in plant. The major results obtained were summarized as follows:1. The results indicated that different interactions of zinc and iron had significant effects on yield, harvest index, seed setting rate and 1000-grain weight. The optimal combination of fertilization for yield was Zn1Fe1. Under the optimal application condition, yield of Liangyoupeijiu and Jiahual could be significantly increased by 4.5% and 5.6%.2. Under the foliar application condition, amylase content of rice was significantly lower than the control. Phytic acid content of two varieties was significantly lower than others under the Zn2Fe0 (0.2%ZnSO4). Under the Zn2Fe0 condition, zinc content of Liangyoupeijiu and Jiahual was increased by 69.75% and 41.65%.3. The two varieties had significant difference in distribution of iron. For Liangyoupeijiu, the optimal combination of fertilization for improving iron content of rice was Zn2Fe2, but for Jiahual, it was Zn0Fe2. When the concentration of zinc sulfate was increased from 0 to 0.2%, the zinc contents in brown rice of Liangyoupeijiu were increased, while that in grain hull was increased and much higher than that in brown rice, and for Jiahual, the zinc content in grain hull was higher too. With the increase of fertilization, more zinc and iron distributed in grain hull and panicle structures. 4. The present research focused on the zinc uptake, partitioning and accumulation in individual organ and the variation in grain zinc mass fraction under pot and field condition. This study suggested major bottlenecks in zinc biofortification in rice:the process of grain filling.5. Under foliar application of zinc on rice seedling growth, not only antioxidase activities but also zinc content of whole rice was increased. Comparative analysis of antioxidase activity, chlorophyll content and zinc content of grain, the study suggested the best foliar application concentration of zinc sulfate fertilizers was 0.2% on seedling growth.6. Zinc sulfate was utilized on different growth stages of rice in the experiment According to the results, seed soaking with zinc sulfate and spraying zinc sulfate on tillering stage could increase the content of chlorophyll in flag leaf. Chlorophyll content is basically constant on flowering spraying experiments. Through the analysis of zinc content and zinc partitioning in individual organ of rice, this study suggested major bottlenecks of zinc transport to seed in rice. By the analyzing the content of chlorophyll and zinc in each organ of rice, the optimum stage with the best methods for zinc sulfate fertilizers application was the foliar application after anthesis.