Abstract:Soybean cyst nematode (SCN) is one of the most destructive pests which damage the production of world soybean seriously. Up to now, we haven’t found resistance genes and it limits the development of resistance breeding; Using molecular markers to locate QTL and find candidate genes which associated with resistance to soybean cyst nematode in soybean to provide the basis of assistant varieties (lines) has profound theoretical significance and practical value. In this study, we use the permanent genetic separation populations and the natural population as material, by using the SCN resistance QTL mapping and association analysis to discover the soybean cyst nematode resistance QTL/genes, and laid foundation for resistance to SCN gene fine mapping and positional cloning.The main results are as follows:1. In the permanent separation of groups, using two different QTL mapping identified two QTLs for resistance to SCN, laid the foundation for map-based cloning of resistance to SCN gene. A F9RIL population which containing166lines was derived from the cross between cultivar Heinong (susceptible to SCN) and Huibuzhi (resistant to many races of soybean cyst nematode). Used MapManeger QTXb17mapping and QTL IciMapping3.0software to construct genetic maps, use WinQTLCart2.5and QTL IciMapping3.0software to QTL mapping. Two QTL loci involved in resistance to SCN3were mapping, one is between Satt163-Satt275on chromosome18(linkage G) explained9.26%-17.93%of the total phenotypic variance in where LOD is3.36-6.84; the second loci near Sattl87on chromosome8(linkage A2) can explained8.61%-8.78%of the phenotypic variance in where LOD is3.08-3.14. According to three standards for resistance to soybean cyst nematode, the resistance QTL loci are are in agreement. Association analysis of the natural population, identified in point7of the SNP associated with resistance to SCN resistance to SCN genes, to create the conditions for gene explore.93SNPs covered the whole-genome were selected among124resistant or sensitive cultivated soybean germplasm and the associated SNP to SCN was fine-mapped after the association analysis. The results show that BARC-017095-02197, BARC-020031-04407, BARC-021321-04035and BARC-025461-06505are only have SNPs in some susceptible germplasms. We can use this feature to determine susceptible materials preliminarily and save time in the breeding of resistance materials; BARC-018019-02497, BARC-030219-06833and BARC-016627-02152, are associated with the soybean cyst nematode resistance, which located Glyma10g24590(Chromosome10), Glymal7g03110(Chromosome17) and Glyma03g34310(Chromosome3). |