Mechanisms Of Zinc Accumulation In Rice (Oryza Sativa L.) Granins

Enriching micronutrients such as zinc (Zn) in staple food, especial in rice through agricultural management is of great significance for human health in developing countries where rice is the main food. There exists significant differences between rice genotypes in response to Zn nutrition, Furthermore; Zn concentration in polished rice can vary very much between different rice genotypes. There offer opportunity to achieve enriching rice Zn genetic screening and cultivate management. However, information about the mechanism to enrich rice Zn is little. This study is summarize out to explore if rice Zn is enriched through field management and how rice Zn between different genotypes responds to Zn supply and regulators. The achievements of this study is mainly as following.1. Foliar spray of Zn at late stage of rice growth increased rice Zn concentration;2. Separately application of N and K fertilizers especially at the late stage of rice growth, increased Zn accumulation in rice grain;3. Rice grain Zn improved by Zn supply, and different genotypes of rice in response to Zn are markedly different. Grain Zn concentration of Biyuahaonuo and 26715 was higher than zhenong921, Zn concentration in polished rice of Biyuzhaonuo was higher than Zn in hulls regardless of Zn supply. By contrast, it was reversed when at 32uM Zn in Zhenong921, ie, Zn in polished rice < Zn in hulls.4. Redistribution of Zn within rice plants was most actively at 8-15d off the peek flowering. During this period, concentration of Zn supply at peek flowering, Znconcentrations in roots, rice ears and grains decreased while flag leaf Zn concentration showed increase first, then decrease later. However, towards to grain maturity, content of Zn in roots and flag leaf was reduce, and it increased in ears and grains.5. Reduce of Zn content in flag leaf of Biyuzhaonuo was greater than Zhenong921.6. Sprays of CTK at peek flowering improved Zn accumulation in flag leaf and delay the ageing of flag leaf. However, this was unfavorable for Zn accumulation in rice grains.