Mapping QTLs For Main Agricultural Traits In Rice And Analysis For A Molecular Marker Which Showed Severe Distorted Segregation

Rice is one of the most important crops in the world, and has become the model crop in plant for genetics and genomic studies. Geneticists and breeders always pay attention to discovering and utilizing the gene of the important agronomical traits in rice. The goal of this study was to research the genetic variance of 9 kinds of important agronomic traits including grain length, grain width, 1000-grain weight and so on by using an F2 population derived from a cross between two cultivated rice germplasms(Oryza sativa L.), HITAR005 as female parent from HITAR and IRGC20509 as male parent from IRRI, some agronomic traits of two parents such as grain length and 1000-grain weight showed severe difference. A molecular linkage map was constructed by using the F2 population and analysis QTLs for these agronomic traits, a total of 17 quantitative trait loci (QTLs) were detected for all studied traits. Meanwhile, analysing a molecular marker showed severe distorted segregation- RI01954, we primary concluded that it closely linked to a novel F1 pollen sterile locus. The results are as follows:1. A molecular linkage map of 54 SSR markers and 37 ILP markers was constructed by using the F2 population, and the length of the map was 1322.1cM with an average interval size of 14.52cM. It is suitable for QTLs mapping.2. All examined traits displayed continued variation and approximately normal distribution, indicating that all of these traits were quantitatively inherited. A total of 17 QTLs were detected for all studied traits:1) Two QTLs for GL were detected on chromosome 6 and 11, explaining 15.4 %and 4.2 %of the total phenotypic variance respectively.2) Two QTLs for GW were detected on chromosome 5 and 9, explaining 8.3 % and 6.9 % of the total phenotypic variance respectively.3) Two QTLs for LW were detected on chromosome 5 and 6, explaining separately 12.7% and 17.6 %of the total phenotypic variance.4) Three QTLs for GWT were detected on chromosome 1 , 3 and 5, explaining separately 8.6 %, 12.5 % and 20.1 %of the total phenotypic variance.