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Corn is one of the important crop in China, occupies an important position in China's agricultural production. Jilin Province is located in one of the world's three major corn belt, is China's largest corn production, yields the highest level of per capita consumption of maize, the amount of commodities, the export volume and redeployment of the amount of the largest maize largest province. Jilin Province has favorable natural conditions for the production of corn, from the promotion of an area or species diversity, Jilin Province, are reflected in a strong foundation for breeding, but there are some difficulties in species management. The purpose of this thesis is based SSR markers for the technical means by screening over 20 countries basic core primers, DNA fingerprint database build validated in Jilin Province in the past five years 174 corn hybrids, and hybrids is validated through the analysis of different years allele frequency, the average number of alleles, average polymorphism information index changes to analyze and discuss the genetic diversity of 174 copies of the test material, the main results of the study are as follows: 1. main findings in this article is to establish a Jilin Province 2005-2009 the 174 audited hybrids DNA fingerprint database, and combined with the characteristics of the original data file exported from the the ABI 3730XL analysis software, and corn as a diploid species characteristics, this article uses two recording modes The data is recorded as the absolute value of the amplified product size, the alleles of each species in each primer sites 2. In this way, compared with the statistics of the number of traditional 0,1 way to greatly reduce the difficulty of the statistics. Analysis of the statistics of the number of alleles, genotypes number draw 40 pairs of SSR primers, polymorphic information content (PIC), and primers distinguish ability (DP value) results can be seen from PowerMarker ver.3.25 software out, this article selected 40 core primers average PIC value of 0.5907, the average DP value of 0.5833, showed high polymorphism and strong ability to distinguish between. 3 Analysis allele frequency variation, the results showed that the 40 pairs of primers in 174 parts of test material detected by the allele frequency variation between donor materials in different years is more obvious, for example, the primer bnlg240k1 detection to allele 237 from 2005 to 2009, the frequency gradually increased, and eventually become a major gene analysis may be due to some gene carrying more control important traits in the breeding process, breeders artificially imposed strong directional selection, making these alleles slowly become a major gene. Primer umc1125y3 allele detected in 151 and 175 is gradually reduced over time and finally disappeared, analysis probably it is not the purpose of directional selection gene, so yearly directional selection, the gradual degradation disappear. This paper studied the evolution of the genetic diversity of hybrids trend of Jilin Province validation in the last five years, the 174 varieties of materials based on validation Year is divided into five parts, from the average number of alleles, average polymorphic index evaluation and analysis of the genetic diversity. Overall, between 2006 and 2009, Jilin Province validated genetic diversity differences are not great, there are still great differences in the four years after the 2005 approved varieties and genetic diversity of a variety of validation .5 the genetic diversity of the 174 copies of chromosome 10 material comparison can be seen from the results, chromosome genetic diversity of the material in 2005 and after four years of material between the still very large differences. 6 The study by PowerMarker V3.25 software, application Rogers 1972 algorithm calculated the genetic distance of the test material, and its clustering analysis, and build the NJ dendrogram. This article turn 12 Gidon material of 20 Jidan material, 12 Jinongda the material chosen, NJ clustering map is re-constructed by the same method. As can be seen from the clustering results tested materials were clustered into three categories, and the Kyrgyzstan the East, Jidan, Jinongda three materials in almost all of these three taxa distribution. The three materials Jilin widely used, representative. Therefore, it can be seen, Jilin Province, roughly three breeding direction.
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