Accumulation of Silicon in Different Genotypes of Oat Grains and Its Relationship with Other Eight Elements

Using environmental scanning electron microscopy and X-ray electron probe microanalysis, Si, P, Mg, K, Ca, S, Cd, Al and Pb content was studied in the cortex, aleuronic layer, near aleuronic layer and center of caryopsis in 22 genotypes of oat grains. The results showed that Si content in different part of 22 genotypes of oat grains changed as cortex>aleuronic layer>near aleuronic layer>center of caryopsis. This implied that Si predominantly deposited in the aleuronic layer for a whole oat caryopsis. Moreover, the considerable difference in Si level also existed among the different oat genotypes, with a comparison of the same portion of different oat cultivars, suggesting that oat genotypes had a dominant effect on Si accumulation. Si content in aleuronic layer was closely related to that in near aleuronic layer and center of caryopsis. Furthermore, a significant non-linear correlation between the content of Si and that of P, Ca, Mg, S, Al, Pb in different parts of oat grains was observed, but no significant non-linear relationship existed between the content of Si and that of K, Cd in the center of caryopsis. The Si accumulation might facilitate the accumulation of P, Ca, Mg, S, Al and Pb.