The Regulation Of Wx,SS?-1 And SBE3 Gene Polymorphism On Eating And Cooking Qualities Of Rice

Rice is one of the major cereal crops and modification of rice quality is a new important objective while improving yield for rice breeding. Rice quality includes rice and paddy. Its appearance and eating and cooking qualities(ECQs) are very important for improving commodity price and life's level. In recent years, the researches about the effects of rice starch synthesis-related genes on rice quality have been carried out. In this study, 67 plants were as test material, which came from Backcross Recombinant Inbred Lines B1F9 of indica photo-thermo-sensitive gene male sterile(PTGMS)line Guangzhan 63S(Oryza sativa ssp. indica) and rice potential restorer line CG173 R with the same alleles of starch synthase?a gene(SS?-3) and granule bound starch synthase gene(Wxb). RVA viscosity, appearance and apparent amylose content(AAC) were measured. Under the condition of test materials weren't classified or they were classified as high, middle, and low types according to AAC, respectively, the correlation of rice RVA profiles with appearance were analyzed. Furthermore, backcross inbred lines(BILs) of BC1F10, BC1F11 generation were utilized and their genotypes, ECQs and RVA profiles were measured among the lines of BILs so that genetic effects for the minor genes SSI, SSIII-1, PUL and SBE3 were analyzed and influence of single gene,two genes interaction and three genes interaction on rice quality were clarified when single gene, two genes or three genes segregated.On the other hand, a line of F4 generation was as materials, which came from a combination of glutinous rice(javanica 22) and CG133 R, a restorer with high AAC by selfing continually to produce a recombinant inbred line. Effect of(CT)n repeat sequence and different haplotypes of Wx gene were identified and analyzed on Wx Expression under the high AAC background. The main results were as follows:1. Significance of correlation between rice chalkiness and most of RVA profiles arrived at 0.05 or 0.01 levels under undefined AAC for test materials. Correlation of ind Exes of rice appearance quality for the materials with middle and high AAC and RVA profiles weren't significant at 0.05 levels if all tested materials were classified as low, middle and high AAC types accord to itself AAC. However, the correlation of riceappearance quality(length, length width ratio and chalkiness) for the materials with low AC and most ind Exes of RVA profiles were significant at 0.05 levels or 0.01 levels.2. In the background of Wxb and SS?-3 genes, the results demonstrated that effects of SS?-1 and the genes interaction between SBE3 and SS?-1 have significant influence on AAC at 0.01level;Interaction effect between PUL and SS?-1 has significant influence on CSV, Pe T and Pa T at 0.01 level. Effects of SSI and the interaction effect of SSI×SS?-1×PUL have significant influence on GC, PKV, HPV,BDV, CPV, CSV and Pa T at 0.01 level.3.The size order of AAC for different SNP combinations of In1G/T and Ex6A/C polymorphisms in Wx gene:In1GG-Ex6A>In1GG-Ex6C>In1GT-Ex6A>In1GT-Ex6C>In1TT-Ex6A; The size order of AAC for different SNP combinations of In1G/Tand Ex10C/T polymorphisms in Wx gene: In1GG-Ex10T>In1GG-Ex10C> In1GT-Ex10T>In1GT-Ex10C> In1TT-Ex10T>In1TT-Ex10 C. The size order of AAC for different SNP combinations of Ex6A/C and Ex10C/T polymorphisms: Ex6C-Ex10C>Ex6C-Ex10T>Ex6A-Ex10T>Ex6A-Ex10 C.The size order of AAC for different SNP combinations of In1G/T, Ex6A/C and Ex10C/T polymorphisms: In1GG-Ex6C-Ex10C>In1GG-Ex6A-Ex10T>In1GG-Ex6C-Ex10T>In1GG-Ex6A-Ex10C>In1GT-Ex6C-Ex10C>In1GT-Ex6C-Ex10T>In1GT-Ex6A-Ex10T>In1GT-Ex6A-Ex10C>In1T-Ex6A-Ex10T> In1T-Ex6A-Ex10 C.The studies have proved that rice ECQs are not only controlled by major genes, but also by minor genes in pathway of starch synthesis, which have important effect on rice quality. Especially, Minor genes and their interaction effects are key factors controlling ECQs when the major genes are same. The functional annotation of minor genes and different haplotypes of Wx have importance for modifying rice quality and improving efficiency on quality breeding.