The Research On Main Agronomic Regulating Factors Influencing Zinc Density In Rice Grain

In this study,field experiments were conducted to screen and identify Zn dense rice cultivars,and understand the effects of the nano-organic zinc foliar fertilizer application on Zn density and bio-availability of in rice cultivars.The interaction of specific endophytic bacteria and soil types on Zn accumulation and bio-availability in rice were studied by pot experiments.The main results are summarized as follows:1.Field screening experiment using 30 rice cultivars showed that rice cultivar Qianyou 0506 is the best quality cultivar,having highest zinc density,lower of phytic acid content,and higher protein content.2.The results of the experiment of spraying nano-organic zinc foliar fertilizer under field condition showed that spray fertilizer increased rice grain yield and biomass yield of different cultivars.The content of zinc in the rice grain was increased by the foliar fertilizer application,and the contents of zinc in the rice grain of different cultivars arranged 15.56?30.65 mg · kg-1 after fertilization.Zn concentrations in polished rice increased by more than 30%for cultivars Xiushui 134,Shenliangyou 884,and Zhejing 88,Meanwhile,the content of phytate in rice was reduced,but the protein content was raised.Analyses using human cell-line for the Zn bio-availability in rice grain showed that nano-organic Zn fertilizer spray increased zinc uptake efficiency by human cells for 14.12%?22.91%,and the total amount of bio-available zinc increased for 14.88%?41.34%by the application of nano-organic Zn fertilizer.3.Inoculation of specific endophytic bacteria promoted the growth and development of rice seedlings,and increased the absorption of zinc by rice plants,with shoot zinc uptake increased by 2.31%to 42.21%,and the root zinc uptake increased by 3.76%?26.09%,respectively.4.Interaction of soil types with endophytic bacteria on Zn accumulation and bio-availability in rice grain were studied through pot experiments.The content of zinc,protein,iron and calcium in polished rice were increased to some extent in the cultivation of different soils.At the same time,the inoculation treatment could reduce the content of phytic acid in rice.In addition,the Zn uptake by human cell lines ranged from 7.65%to 12.45%,and the total available zinc ranged 1.63-4.10 ?g·g-1.for different treatments.In the case of non-inoculation,Zheyou 12(zinc high density cultivar)and Zheyou 18(zinc low density cultivar)cultivated on Purple soil was the best in terms of Zn bio-availability.After inoculation,,the zinc uptake rate by human cell lines increased by 33.44%and the total bio-available zinc increased by 64%,respectively for Zheyou 12 which was cultivated on red soil.Whereas the zinc absorption rate was increased by 25.62%and the total bio-available zinc increased by 75.46%for Zheyou 18 after inoculation with endophytes grown on red soil.