QTL Analysis Of Nine Quality Traits Using Three Sets Of Chromosome Segment Substitution Line Populations In Rice (Oryza Sativa L.)

Rice is our country’s and the world’s largest food crop, approximately 65% of the world’s population eat rice as a staple food. China is a big country in rice production and consumption. Since the introduction of hybrid rice, China’s rice production has been greatly improved, but the quality is slowly improving. Recently, with the change of people’s living standards and consumer attitudes, quality requirements for rice gradually tend to focus more on nutrition and health. Besides, as China’s rice have worse quality compare to other rice producing countries in the world (such as Japan, Thailand, Australia), which leads to weak international competitiveness in rice market. Enough attention has been towards this issue to improve rice quality problems by majority of rice scientist and breeders. Pursuit of high-quality rice is the major goal of these rice breeders. Now, evaluation of the rice quality varies, but includes a good milling quality, appearance quality, cooking quality, high protein and amino acid content.In this study, three rice chromosome segment substitution lines (chromosome segment substitution lines, CSSLs) populations on rice milling quality, appearance quality and cooking and eating quality of 9 traits were measured in two consecutive years, combined with molecular markers, QTLs which controlled these nine traits were detected by QTL IciMapping software.The main results were as follows.1. In the Nipponbare/Kasalath//Nipponbare NKa-CSSL population consists of 54 families, coefficient of variation ranged from 11.17% to 103.3%,broad sense heritability ranged from 60% to 90%,and performences are stable between years.18 QTLs which controlled these nine traits were detected in 2 years.4 QTLs which control brown rice rate are respectly located on chromosome 1,3,4andl 1,1 QTL which control milled rice rate was located on chromosome 11,1 QTL which control head milled rice rate was located on chromosome 11,5 QTLs which control chalky rate are respectly located on chromosome 1,4and6,2 QTLs which control size of chalky are respectly located on chromosome 6and8, 3 QTLs which control chalkiness degree are respectly located on chromosome 1and6,2 QTLs which control gel consistency are respectly located on chromosome 7 and 8,4 QTLs were detected both in 2012 and 2013. They are qCS6, qCS8, qCD6and qGC7.2. In the Nipponbare/Koshihikari//Nipponbare NKo-CSSL population consists of 48 families, coefficient of variation ranged from 6.72% to 71.37%, broad sense heritability ranged from 60% to 90%, and performences are stable between years.10 QTLs which controlled these nine traits were detected in 2 years.2 QTLs which control brown rice rate are all located on chromosome 6,1 QTL which control head milled rice rate was located on chromosome 6,3 QTLs which control chalkiness degree are respectly located on chromosome 2and3,1 QTL which control gelatinization temperature was located on chromosome 1.3. In the Nipponbare/Koshihikari//Koshihikari NKo-CSSL population consists of 41 families, coefficient of variation ranged from 6.67% to 48.89%, broad sense heritability ranged from 60% to 90%, and performences are stable between years.4 QTLs which controlled these nine traits were detected in 2 years.1 QTL which control milled rice rate was located on chromosome 1,1 QTL which control head milled rice rate was located on chromosome 1,1 QTL which control chalkiness degree was located on chromosomel0,1 QTL which control amylose content is located on chromosomel.Among the QTLs detected both in 2012 and 2013 in three populations 3 QTLs were newly discovered. They were qCD,qCS% and qAC1. These QTLs could be used for improving milling, appearance and cooking and eating qualities in rice.