Pyramiding Effects Of Cooked Rice Elongation Qtls Based On SSSLs In Rice(Oryza Sativa L.)

Rice is one of the most important food crops in the world.It has very important significance for crop genetic improvement to identify and map agronomic trait locus,and apply them in pyramiding breeding.Cooked rice longation(CRE)is a quantitative trait controlled by multiple micro-effective genes,which is the ratio of rice grain length to cooked rice grain length.It is also an important index for evaluating cooking and eating quality of rice.Single segment substitution line(SSSL)eliminates the interference of genetic backgrounds,and it’s one of the important materials of quantitative trait loci(QTL)mapping and polymerization.It’s significant for improving rice quality to polymerize QTLs from SSSLs.In this study,based on the method of molecular marker assisted selection,a number of multi-segment polymerized lines with more segments were verified,by using 11 multi-segment polymeric materials and 219 multi-segment polymerized lines,the polymerization rate of these aggregates was measured and the polymerization effect was analyzed.The main results are as follows:1)The validity of fragment information of 219 multi-segment polymerized lines was verified,including 10 two-segment polymerized lines,5 three-segment polymerized lines,23 four-segment polymerized lines,40 five-segment polymerized lines,39 six-segment polymerized lines,54 seven-segment polymerized lines,5 eight-segment polymerized lines,26 nine-segment polymerized lines and 17 ten-segment polymerized lines.2)The CRE of 219 multi-segment polymerized lines was determined and the epistatic effect was analyzed.The results showed that the elongation of rice grains of the multifragment polymerized lines was better than that of the recipient parents,and the elongation of rice grains increased with the increase of the number of polymerized fragments,while the epistatic effect was negative on the whole.3)Among 219 pieces of multifragment polymerized materials,the grain elongation of some materials was relatively high in the early and later seasons,and the phenotype was relatively stable.In this study,a number of multi-segment polymeric materials with better cooked rice elongation were obtained by polymerizing QTLs of CRE,which could be applied to breeding practice and provide references and ideas for the cultivation of high yield and high quality.