Selection Of Enriched Iron Content Of Rice Germplasm Resources And Genetic Analyses And QTL Mapping For Iron Content In Rlce Grains

Iron is one of indispensable trace elements for human body to maintain normal physiological functions.This study using Atomic Absorption Spectrometry to measure iron content of rice grains for102germplasm resources in ningxia,and select the Rice varieties of enriched Iron content.The difference of grain iron content between different varieties were analysed,correlations between Iron content of rice grain and grain shape traits were discussed. What’s more, Ningnong Heijing within high iron content and Jingxiang-1within low iron content was crossed to get F2segregation population,genetic analysis of grain iron content for F2population was carried out;A genetic linkage map was constructed.The control of grain iron content QTL mapping and genetic effect were analysed;The number of QTLs and the location in chromosome were detected,laying the foundation for breeding iron rich rice in ningxia.The results were summaried as follows:1This study using atomic absorption spectrometry to detect the content of rice grain iron found that, the difference of iron content in different rice varieties was significant,and the overall content is low;The iron content of Ningxia land races and Introduced varieties was compared,and the t test results shown that the iron content difference between Ningxia land races and Introduced varieties was not significant.2Several Iron-rich Rice varieties were selected from102rice germplasms:Aixuenuo, Ningnong heijing,Changli-5and Yang he white rice.The iron content were80.93mg/kg,48.44mg/kg,36.25mg/kg and25.00mg/kg,respectively.3Iron content was significantly positive correlated with grain length and the ratio of grain length to width,negatively related to grain thickness,and uncorrelated to grain width and1000-grain weight.Among the several higher iron content varieties,Ningnong heijing and Ai xuenuo were belong to black rice varieties,the high iron content may be associated with the pigment in black rice.4The analysis of the frequency for F2population grain iron content,the result shown that,the average iron content close to the parent whin low content,appeared the phenomenon of transgressive segregation;the frequency distribution histogram was close to a unimodal skewness normal distribution, it indicated that iron contents of rice grains was controlled by multiple genes,it is suitable for QTL analysis.5The QTL analysis was conducted using the interval mapping.A genetic linkage map,contained130SSR markers,was constructed.The map covered a total of3183cM with an average interval of24.48cM.6QTLs related to Fe in rice grain was detected by using interval mapping.There are QTLs8QTLs for Fe content located on chromosome3,4,5,7,9,12,which contribution rates varied from6%-12%.The additive effects all come from NingnongHeijing within high iron content.On chromosome4,there are3QTLs related to Fe content,which located on three adjacent segment,RM6997-RM3367,RM3397-RM1155and RM1155-RM6997,contribution rate were12%,11%,12%,respectively.In this genome segment,it may exists gene cluster control the synthesis of iron content.Loci on chromosome4,9,12contribution rate is relatively high,these sites should be as a key test in the molecular assisted breeding of high iron content.