Identification Of QTL Of Protein And Amino Acid Content By Ril In Rice

Protein is the second most abundant constituent of milled rice, following starch. As one of the staple food, rice is one of the most important protein sources for people.Because of the relative complication in evaluating protein and amino acid content compared to other quality traits in rice, it is difficult to improve the content of protein and amino acid by conventional breeding. With the advent of molecular marker, introgression of genes controlling good quality by marker-assisted selection has been proved to be an effective choice to improve the quality of cultivars. However, the genetic basis of protein and amino acid content is complex and often controlled by quantitative trait loci. Thus, mapping those QTL underlying protein and amino acid content is needed for rice genetic improvement. In the years of 2008 and 2009, the phenotypes of protein content,17 kinds of amino acid content and total amino acid content were collected using the F9 RIL population from the cross between Zhongguoxiangdao and Chuanxiang29B. The main results were as follows:1. The result of t-test showed that the protein content and aa content were significant difference (p=0.01) in the two years of 2008 and 2009. Two-way recombinant inbred lines showed transgressive segregation, similar to normal distribution. Significantly positive correlations were found between 2008 and 2009 in the same trait.2. A total of 6 QTLs were identified for Protein content were mapped on chromosome 3 and 6, each of the main-effect QTLs individually explained 4.40%-9.16%of the phenotypic variations, and pcx6-3 can be detected in both two years.3. A total of 52 QTLs were identified for aa content were mapped on chromosome 1,3, 4.6,8,9,11,12, each of the main effect QTLs individually explained 3.64%-12.25% of the phenotypic variations, and the fragment between RM253-RM249 and RM1663-RM261 can be detected in both two years.