Construction Of SSR Molecular Marker Genetic Linkage Map In Sunflower

Oil sunflower is a salinity-resistant, drought and barren resistance, wide adaptability oil crops, with high economic efficiency, which is one of the world’s top five oil crops, mainly distributed in China’s north, northwest, northeast of the semi-arid, arid regions, such as Inner Mongolia, Xinjiang, Heilongjiang. In these areas, due to inadequate or uneven distribution of rainfall or irrigation, making the sunflower production often suffer from drought stress, so water-conservation and drought-resistant is the important measures to ensure that sunflower high and stable yield, and it is also the genetic improvement of sunflower breeding objectives. Due to the amount of crop drought resistance traits belong to a complex quantitative traits, the genetic improvement of drought resistance molecular breeding which based on the molecular marker linkage maps and gene mapping,has become an efficient breeding method. Oil sunflower molecular marker genetic linkage map construction, is the foundation of gene mapping, contains a great significance for drought-resistant related traits of gene mapping, map-based cloning and molecular breeding. This paper selected two varieties K55, K58as parent materials which have significant difference based on the drought resistance, then got get RIL F4lines. Finally, selecting the SSR markers to build an oil sunflower molecular genetic map preliminary.(1) established a RIL group, It crossed F1generation that two optional K55and K58(K55is weak resistant inbred lines, K58is strong resistant inbred lines) Significant difference was found in drought resistance. and then got F4continuous selfing through the way of single grain, a total of194strains. Study for this test.(2) stable SSR reaction system is established, The main factors influencing SSR-PCR including the concentration of Mg2+, dNTPs, Taq polymerase, primer and annealing temperature were investigated. The optimized SSR-PCR amplification system was dNTPs200μM, Mg2+2.5mM, Taq polymerase0.5U, primer0.4μM, Annealing Temperature54℃.(3) Selecting150SSR primers with polymorphism between parents out of500, signific ant difference was found in85polymorphic primer amplification in groups of get the expected result.. Through the statistics, a total of227polymorphic products and made a coseparation analysis, finally get111marker loci to complete map building work.(4) By the chi-square test analysis of segregation distortion happened20mark, segr- egation distortion ratio was18.02%. Which bias K55parents have five markers, bias hetero zygous genotype tag has five, to favour K58tag has10marking accounted for50%of all partial segregation ratio.(5) Via joinmap4.0to construct genetic map, The map has built17chain groups, contains78SSR markers, covering the entire genome length is680.4cM, Most large distance of52.2cM and the minimum distance of2.3cM, the average spacing of8.72cM. On the map, the third linkage group exist a segregation distortion region which contain all the tags to K58.