| In this research, SSR markers were used to identify genotype map of Harosoy SILs (Segments Introgressed Lines). It aimed to make clear the segment size, number and distribution among chromosomes carried by introgressed chromosomal segments, and identify gene loci associated with known genes and agronomically important traits of soybean, and provide foundation for further fine mapping and novel gene mining as well.The main results are as follows:1. Identification of 112 SILs by SSR markers. 471 SSR markers scattered among 20 chromosomes were chosen according to soybean public genetic map with an average distance between markers about 10cM. Of these markers selected 243 SSR markers were polymorphic between one or more SILs and Harosoy and Clustering analysis showed that similarity coefficient between SILs ranged from 0.85 to 0.99, and the scope of similarity coefficient between SILs and recurrent parent was 0.87～0.99 indicated little difference among genetic background of SILs mainly inherited from Harosoy. 1030 introgressed segments, including 693 homozygous introgressed segments and 337 heterozygosity introgressed segments respectively, were identified by 243 polymorphic SSR markers in 112 SILs, each SIL contained 9.2 introgressed segments on average. The number of introgressed segments ranged from 2 to 26 and the total length of introgressed segments was 4594cM with an average length of 4.5cM. And the length of each SIL ranged from 6cM to 133.5cM. Overall introgressed segments covered 89.6% of the whole genome, and 12 of 20 chromosomes were over 90%. The genetic background recovering ratios calculated either by marker numbers or introgressed segments length were lower than the theoretical value.2. Identification of 11 SSR loci associated with known genes. Based on analysis of SSR markers and graphical genotype over SILs, 8 loci and 7 marker intervals related to 11 known genes were identified, and 5 of which were in accordance to previous mapping results by classic genetics or other mapping methods, and the rest of loci identified were about 10cM distant from documented results. What was worthy to be pointed out was marker intervals associated with Rj2-Rps2-Rmd and T-E1 were shortened from 16.76cM and 5cM to 6.32cM and 0.4cM respectively.3. QTL mapping of agronomically important traits in soybean preliminarily. 190 markers related to 10 important agronomically traits were mapped by agronomic traits data from 4 different sources. Out of which 28 SSR markers related to 5 traits were mapped repeatedly by data from different sources indicated these QTLs were influenced by environmental conditions limitedly or had larger contribution rate. Besides, 52 markers related to two or more traits simultaneously were identified, showed that QTLs in these regions were closely linked or these QTLs were pleiotropy. Additionally, we also identified 6 QTLs related to 4 qualitative traits. |
