Assessment of Some Heavy and Essential Elements Accumulation in Seeds and Leaves of Parent and Introgression Lines in Oryza sp.

In this study, element concentrations in grains of three wild rice species (i.e., Oryza rufipogon, Oryza officinalis and Oryza meyeriana) and three cultivated rice varieties (i.e., Nipponbare, 93-11 and HY-8) as well as in leaves of Oryza officinalis and its introgression lines were measured. The wild rice species were highly useful in terms of the quality and the harmful heavy metal resistance. The results showed that the mean concentrations of heavy metals in the soil was in the ranking order of Ti > Zr > Sr > Pb > Rb > As. The essential element concentrations, it was found that the ranking order was Ca > Fe > K > Mn > Zn > Cu > Mo. In grains, the content of Ca, Zn and Sr elements in wild rice species was higher than that of cultivated rice varieties. Oryza meyeriana had the highest content of Ca and Sr, and Oryza officinalis had the highest content of Zn. The levels of Mo were high in Oryza rufipogon, while extremely low in Oryza officinalis and Oryza meyeriana. Oryza officinalis had much higher Cu than other varieties. Bioaccumulation values of all elements were less than one in the rice grain. The concentrations of elements varied in different parts of rice plants, and the highest concentrations occurred in the leaves comparing with grains. The introgression lines i.e., FC7-12, FC7-6, FC7-20 and FC7-1 showed good performance and ability in heavy metals resistance. High genotypic and phenotypic variances were observed in Mn concentrations followed by Fe concentrations, respectively. This study preliminarily proves that there is genetic diversity in element absorption and accumulation among different genotypes of wild rice species, cultivated varieties and introgression lines. Wild rice species are useful for developing high quality and improving tolerance to heavy metals in modern rice cultivars.