Vitamin A Synthesis Related QTL Mapping In Functional Rice Zibaoxiangnuo 1

Rice is the staple crop for more than half one of the world population,its nutritional value has a very important role in the diet.The functional rice,as a new and special rice variety,has some special composition to balance and adjust to the body's physiological functions.So far,Zibaoxiangnuo 1 is the first functional rice in the world,which contains natural endogenous genes derived from cultivated rice associated with vitamin A?VA?,and its VA content is 11 IU/100g.In the experiment,we used Zibaoxiangnuo 1 and 93-11 to do reciprocal crosses,and generated F₁ generation and F₂ population.Through measuring the VA content of each plant we could analyze the genetic mechanism of the VA trait.Meanwhile we built a recombinant inbred line?RIL?derived from Zibaoxiangnuo 1 and Minghui 63 by A single pass.Then we structured a genetic mapping,and mapped the QTLs controlling VA trait in rice and carried out effect analysis.Finally,we mapped three QTLs about VA trait,this would provide the foundation for fine mapping of genes and breeding some new rice varieties containing a lot of VA.The main findings are as follows:1.We measured the VA content of the reciprocal cross F₁ generation and F₂ population between Zibaoxiangnuo 1 and 93-11,found the seed of F₁ generation doesn't have VA,the VA content of 200 lines from F₂ generation ranges from 0 to 233.87 IU/100g,among them there is 30 families containing VA.These results indicate the VA phenotype in rice is quantitative traits controlled by invisible nuclear genes.2.We searched for polymorphic primers between Zibaoxiangnuo 1 and Minghui 63 using 516 pairs of SSR primers,and found that 323 pairs primers is polymorphic.Then we selected 156 pairs of markers,which have good polymorphism and there is 10 cM in either one.Finally,we constructed a rice genetic map via genotyping about 200 lines of RIL population,the total map distance of this map is about 1084.91 cM.The map distance between markers ranges from 0.27 to 27.95 cM,and the average distance is 7.53 cM.So we say the map is in good accordance with the high-density map published.3.We selected 153 families from RIL,which has the amount sufficient seed,measured the VA content.There are 111 lines which contain VA,and 42 lines excluding VA.So we found a continuous distribution about VA content of Brown in the population,and the content of each family varies between two parents.4.We mapped and analyzed QTL about VA content of brown rice for RIL population by using complete interval mapping?ICIM?.Three QTL related to vitamin A synthetic were found,which are located on the 5th and the 6th chromosome,the contribution rate of 9.25%,18.95%,8.99%,respectively.The QTL between RM3187 and RM3827 on chromosome 6 is a main effect QTL,the favorable gene originated from Zibaoxiangnuo 1,should be the important portion for fine positioning and assisted breeding.