QTL Analysis On Mineral Elements Content In Rice

About four to five billion people in the world suffer from micronutrient elements deficiency, sub-health and many diseases due to lack of mineral elements. Rice is the staple food of more than fifty percent of the world's population, so it's important to discovery and use the rice varieties which accumulate micronutrient elements on the protection of human health. We developed a recombinant inbred line population with 184 lines, derived from a cross between Chuanxiang 29B (Oryza sativa indica) and Lemont (Oryza sativa japonica), planted in Yingzhou of Hainan province in the winter of 2008,and in Chengdu of Sichuan province in the summer of 2009. The Ca, Fe, Mn, Zn, Cr contents of the brown rice were detected by full spectrum of direct plasma spectrometer of Shimadzu Corporation. The QTL analysis was conducted using the composite interval mapping. The major results were as follows:1. A genetic linkage map, contained 98 SSR markers, was constructed. The map covered a total of 1244.8cM with an average interval of 17.25cM.2. The analysis of correlation between 5 mineral element contents indicated that there was a significant positive correlation between Ca content and Fe, Mn content, between Fe content and Zn, Cr content, between Mn content and Zn content, between Zn content and Cr content. Fe content had a positive correlation with Mn content, but Fe content had no significant positive correlation with Zn,Cr content in rice which were planted in Yingzhou of Hainan province. The 5 mineral element contents had similar correlation between each other in rice which were planted in Chengdu of Sichuan province.3. The six QTL of 5 mineral elements contents in brown rice were identified, which were planted in Hainan province, only one QTL were detected to control Ca content, distributed on the 2th chromosome, the LOD score was 2.99, explained 6.71% of the total phenotypic variance. Only one QTL controlled Fe content on the 7th chromosome, the LOD score was 3.45, the QTL explained 7.84% phenotypic variation. Only one QTL called qHZn-3 was detected to control Mn content on the 3th chromosome, the LOD score was 7.65, explained30.20% of the total phenotypic variance. The two QTL controlled Zn content, distributed on the4th and 7th chromosomes, the LOD score were 4.57 and 3.87, these QTL explained 13.82% and10.97%phenotypic variation. Only one QTL controlled Cr content on 5th chromosome, the LOD score was2.30, the QTL explained 6.27% phenotypic variation.4. The nine QTL of 5 mineral elements contents in brown rice were detected,which were planted in Sichuan province, Only one QTL wwas found to control Ca content, distributed on the 7th chromosome, the LOD score was2.99, explained 8.03%of the total phenotypic variance. Only one QTL controlled Fe content on the 7th chromosomes, the LOD score was 3.56, the QTL explained 8.75% phenotypic variation. The two QTL were responsible for Mn content on the 3th and 8th chromosomes, these LOD score were 7.91and 2.29, explained 20.01% and 4.37%of the total phenotypic variance,there's a major QTL called qSMn-3,on the3th chromosome, it was also near the marker RM3684 as qHZn-3 which was found in Hainan RIL to control Mn content. The four QTL controlled Zn content, distributed on1th,5th,6thand 7th chromosomes, the LOD score were a range of 2.51-3.68, these QTL explained a range of 7.10%-11.61% phenotypic variation. Only one QTL controlled Cr content on 8th chromosome, the LOD score was 2.30, these QTL explained 5.34% phenotypic variation.