QTL Analysis On Content Of Mineral Elements In Rice Of Backcross-inbred Lines Derived From Oryza. Longistaminata

Rice is one of the principal source of mineral elements for human health. Mineral elements including mineral nutrition elements and heavy metals, and mineral nutrition elements play an extremely important role on normal growth of plants and animals. Simultaneously, toxic heavy metals are not only harmful to plants' and animals' healthy growth, but also lead to environmental pollution. It is significant to understand the genetic mechanisms of the mineral elements in rice grains, which will help us to breed green rice with high trace elements and low heavy metal elements. In order to explore the genetic variation and correlation among the content of Fe, Zn, Se, Cd, Hg and As in brown rice, we analyzed the QTL for contents of these mineral elements in brown rice using a backcross inbred line (BIL) population with 148 individuals derived from the cross of wild rice Oryza longistaminata×9311. The results were summarized as follows:1.In Huashan and Ezhou, the contents of Fe, Zn, Se, Cd, Hg and As in the148 BILs showed a continuous distribution. No significant differences for the 6 mineral elements in backcross parent 9311 were observed in the samples from Huashan and Ezhou. Similar patterns for the contents of the 6 mineral elements were detected in the 148 BILs.2. From the variation coefficient of the 6 mineral elements contents, Cd, Hg and As were significantly higher than that of Fe, Zn and Se. Significant positive correlation were observed between Zn and Se,a negative correlation were observed between Fe and Cd, As and Hg, both in Huashan and Ezhou. Significant correlations between Zn and Hg in Huashan, Fe and Zn, Fe and As in Ezhou were detected, respectively.3. There were 38 putative QTLs located on chromosome 1?12 for Fe, Zn, Se, Cd, Hg and As contents in brown rice were identified in population, that planted in Huashan. The LOD score of the QTLs were ranged from 2.49 to 47.75, and the QTLs accounted for 5.32 ?70.87% of the trait variance. Fifty putative QTLs for Fe, Zn, Se, Cd, Hg and As contents in brown rice were identified in population, that planted in Ezhou. The 50 putative QTLs located on chromosome 1?12. The LOD score of the QTLs ranged from 2.58 to 17.07, and the QTLs accounted for 4.09-50.38% of the trait variance.4. Three QTLs for Hg were identified both in Huashan and Ezhou. They located at 12.81 Mb on chromosome 1, at 26.04 Mb on chromosome 3 and at 1.14 Mb on chromosome 11, respectively. It suggests that may be major genes controlling the content of Hg is located in the three QTLs.