RESUMO
In the present paper, the contents of 8 elements in brown rice of 789 accessions core collection for rice landrace from 16 prefectures of five rice regions in Yunnan province were determined by ICP-AES technique. The method proves to be simple, rapid, highly sensitive and accurate, and can be used to determine many elements at the same time. Its recovery ratio obtained by standard addition method ranged from 97.1% to 110.2%, and its RSD was from 0.7% to 4.4%. The analytical results showed that the elemental concentrations (mg x kg(-1) ) in brown rice are in turn of P(3 834.83 +/- 486.49) > K(2 567.72 +/- 336.74) > Mg (2 567.72 +/- 336.74) > Ca (153.67 +/- 55.90) > Zn( 33.35 +/- 13.65) > Fe(32.08 +/- 25.51) > Cu (14.22 +/- 11.85) > Mn(13.58 +/- 3.22). The highest P content is in brown rice from the northwest Yunnan with the rich nonferrous metals and most abundance of biodiversity in the world, the highest Ca, Mg, Fe and Zn concentrations are in brown rice from the middle Yunnan with early cambrian fauna and phosphorite enrichment, and the highest Cu and Mn contents are in brown rice from the southwest Yunnan with the prominent crop diversity. The distributing zones with the highest P and K, middle Ca, Mg and Mn and lowest Fe and Zn in Yunnan are the enrichment zone of minal resources and largest biodiversity. As far as we know, this is the first report that the zonal characterstics of mineral elemental concentractions in brown rice are associated with a lot of factors, such as biodiversity center, enrichment zone of minal resources, origin of life, mountain ranges and rivers and so on, and further it was deduced that the asymmetry of distribution for mineral elements and its reciprocity of mountain ranges and rivers are the key of origin of life. The above results provided reliable data and theory bases for the malnourished Fe and Zn and Ca for 4 billion people in the world, origin of life, the genetic breeding and production of functional rice.
