中文摘要：

米锌浓度、植酸含量以及植酸与锌的摩尔比均明显低于糙米.大气 CO 2浓度升高使精米和糙米锌浓度平均下降5％和7％，锌处理使对应部位锌浓度分别增加40％和63％，差异均达极显著水平，但施氮量或栽插密度处理对两部位锌浓度影响未达显著水平.CO 2浓度和锌处理对精米和糙米的植酸含量均无显著影响，但增加施氮量和移栽密度使糙米植酸含量分别下降8％和6％，差异均达极显著水平.大气 CO 2浓度升高使精米和糙米中植酸与锌的摩尔比平均增加6％和7％，锌处理使对应部位植酸与锌的摩尔比分别下降28％和40％，增加施氮量和移栽密度使糙米中植酸与锌的摩尔比平均下降10％和7％.说明高浓度 CO 2环境下超级稻Ⅱ优084食用部位微量元素锌含量下降且生物有效性降低，但适当增加施氮量或移栽密度特别是结实期叶面喷施锌肥，可不同程度地改善该品种稻米的锌营养水平.

英文摘要：

Elevated atmospheric CO2 concentration （[CO2 ]）increases rice yield,but little is known about effects of [CO2 ]on Zn bioavailability of edible parts of rice,as well as the agricultural practices which can improve micronutrient status of rice under high CO2 environment.By using a Free Air CO2 Enrichment （FACE）facility installed in paddy field,super rice Ⅱ-you 084 were grown under two levels of CO2 concentration （ambient and 50% higher than ambient）,N application （1 5 and 25 g/m2 ）,planting density （1 6 and 24 hills/m2 ）and foliar Zn application （0% and 0？2% ZnSO4 ）.At maturity,in milled and brown rice Zn and phytate concentrations were analyzed,molar ratio of phytate to Zn were calculated.The results showed that compared to brown rice,milled rice had much lower Zn concentration,phytate concentration and molar ratio of phytate to Zn.Elevated [CO2 ]significantly decreased Zn concentration of milled and brown rice by 5 % and 7%,respectively;Foliar Zn application significantly increased Zn concentration of milled and brown rice by 40% and 63%,respectively.However,the changes of N application and planting density had no effects on rice Zn concentration.Phytate concentrations of milled and brown rice were not affected by either CO2 or Zn treatments,but higher levels of N application and planting density significantly decreased phytate concentration of brown rice by 8% and 6%,respectively.The molar ratios of phytate to Zn in milled and brown rice were significantly increased at elevated [CO2 ]in average of 6% and 7%,but decreased under foliar Zn application by 28% and 40%,respectively.The high levels of N application and planting density had little effects on molar ratio of phytate to Zn in milled rice,but in brown rice,it decreased by 10% and 7%.Our results indicate that the content and bioavailability of micronutrient Zn in edible part of rice Ⅱ-you 084 will be lower under future high CO2 environment, but modification of agronomic practice such as ample N application,increase of planting d