Identification of QTLs for Important Quantitative Traits in Rice Clonally Propagated F2 Population
|Course||Crop Genetics and Breeding|
|Keywords||Rice F2 generation clonal groups Quantitative traits SSR markers QTL mapping Related traits Gene linkage|
Rice is an amazing plant, feed nearly half of the world's population. However, the rice many important agronomic traits are polygenic control the number of traits affected by environmental conditions larger. Although most of the studies of the genetic breeders around the improvement of quantitative traits, but to be precise use of quantitative trait breeding quality multi-resistant super high also more difficult, mainly due to the genetic basis of quantitative traits studied enough thorough. Since the 1980s, the rise of molecular markers and QTL mapping method improved for the detailed study of quantitative trait effective means. F 2 groups in genetic research, most informative, reliable phenotypic data but can not be obtained due to experimental error can not be estimated. In this study, by the japonica varieties Balilla wide compatibility and indica varieties Dular the F 2 seed tissue culture asexual reproduction by 250 stable clones consisting of F 2 -generation the groups (Clonally propagated F 2 population F 2 CP). In order to the the F 2 CP for the study in 2000 and 2001, a total of 20 important agronomic traits inspection and statistical analysis, in the 2001 planting F 2:3 > The pedigrees groups to the same study, in order to compare two groups of performance. Constructed by SSR markers detected molecular marker linkage map, using interval mapping and composite interval mapping QTL identification and analysis of various traits. The main findings are as follows: 1. In all missions trait, F 2 CP and its F 2:3 groups showed an approximate normal distribution, the performance of transgressive segregation, two-year distribution trends consistent. Plant morphology, panicle and grain the three categories traits internal and classes widespread phenotypic correlation. 2. Information with screened 141 SSR markers value analysis F 2 CP genetic composition, the Balilla and Dular on the average genetic contribution of the entire group, respectively, 0.49 and 0.51, similar to the theoretical ratio of 1:1, Population genetic composition approximately normal, slightly biased in favor of Dular. The chi-square test, only 31 (22.0%) marker segregation distortion performance. 3.138 SSR markers constitute the average map covering 12 rice from 14.7cM, labeling sequence tag Temnykh partial separation occurs, 26 favor of the pro-Dular, chromosomes SSR linkage map, between adjacent markers consistent order. 29 (21.0%) were located on chromosomes 1, 2, 3, 6, the other three in favor of the Balilla, location on chromosome 1 and 9. Using the interval mapping method on each trait QTL mapping, test groups of seven plant type traits repeated a total of 24 QTLs detected the the eight FZCP panicle traits a total of 31 repeat positioning QTLs for five grain 23 QTLs, many of the same traits QTLs for traits were found, in particular, the main effect of using QTL information in different repeat and repeat groups well. Different mode of action of these QTLs, grain weight, grain length, grain width, length and width of the plot and the aspect ratio of 5 Kernel Traits mainly controlled by the additive effect. 5. Locate the QTLs for each trait composite interval mapping more than interval mapping method, two detection methods, the QTLS most of all consistent, only some small effect QTLs appear in a particular method of positioning results. 6 the QTL for positioning results, synergistic and reduced efficiency of alleles is dispersed in the genome of the parental, but more from the high value of the parental alleles. 7. Related traits of the genetic basis of a QTL tightly linked, or pleiotropism. Some QTLs and the corresponding major gene traits tightly linked, or the seats different alleles of the same chromosome. 9. Both for General Genetics, or build a molecular linkage map and identification analysis the gene molecular genetics and breeding the research, FZCP is a very practical separation groups.