| In this study, with two optional inbred lines K55, K58 as parents, it crossed F1 generation, F1 selfing get F2, finally obtain a F6 RILs populations which contain 187 plants by single-seed descent method as the experimental materials. Then use these materials construet a genetic linkage map of oil sunflower by using SSR molecular marker technology and conduct the quantitative trait loci (QTL) on germination and seedling stage, thus providing theoretical basis for map-based cloning and develop molecular marker to assist breeding of agronomic character, etc. The main results on this study were as follows:1.46 suitable primers were used for SSR designed and 129 polymorphic loci were acquired by PCR amplification of 187 individuals in F6 RILs population, then combine these 129 ioci with our laboratory existing loci, we finally got 313 loci. We detected 130 loci were deviated from Mendelian segregation ratio, which accounted for 41.5% in total.2.Via JoinMap 4.0 we construct a oil sunflower genetic map which contain 17 chain groups. Removing the loci which deviate from Mendelian segregation ratio seriously firstly, then use the rest 271 loci construct the genetic map. There were 165 loci in this linkage map in total and the length of the linkage map was 1230.0cM.The longest linkage population was the 1st map, the length was 229.7cM;the smallest linkage population was the 17th map, the length was 2.3cM.3.The agronomic character indices including 9 characters under two different supply water conditions and 9 characters about seedling stage measured in the field, the former include germination rate, sprout potential, germination index, etc; the latter include emergence rate, the upper ground weight, root weight, etc. Then analysis of variance on the above characters, the results presented significant or over significant differences between the 187 strain and it in the range of normal distribution. The above results indicated that these characters suited for QTL mapping.4.Correlative analysis indicated that no matter the indicators related to the germination period under two different water conditions or the indicators measured in the field, there is a certain degree of correlation between them. It shows significant or over significant positive correlation between characters under two different supply water conditions. In the characer index measured at seedling stage in the field, the root fresh weight and chlorlphyll content, leaf number and leaf area present a very significant positive correlation, the root dry weight and leaf number present a significant positive correlation.5.Taking LOD=2.5 for critical value to analyze the localization of activity of 18 agronomic characters by using the software QTL IciMapping 4.0. The results showed that there were 12 QTL controlled 8 agronomic characters and the 12 QTL distributed on 5 linkage groups, and the distribution was uneven in each group. The most distribution was on the 1st group with 5 QTL; the least distribution was on the 7th and the 10th with 1 QTL on each group. There was each one QTL controlled sprout potential and germination index under drought stress conditions; there was one QTL controlled germination index,2 QTL controlled radicle fresh weight and 1QTL controlled the fresh weight of embryo bud under the normal water supply condition; in the field measured seedling traits, there were 2 QTL controlled root fresh weight,3 QTL controlled shoot dry weight and 1 QTL controlled leaf area. |
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