Genetic Diversity And Population Structure Of Inbred Lines

Maize is one of the most important cereals and forage crops in China,and plays a key role in Chinese agriculture.Genetic diversity and heterotic grouping among maize germplasm are fundamentally important in mazie breeding.But narrow genetic base resulting from the decrease of gengtic diversity is one of important reasons of different breakthrough in mazie breeding. Revealed by simple sequence repeat auto-fluorescence detection,we analyzed the genetic diversity and population structure of core lines.And the results were as follows:1.84 SSR loci distributed in the maize genome were used to evaluate the genetic diversity of the136 inbred lines.A total of 756 alleles were detected,the average of alleles per locus was 9, and the average gene diversity and PIC was 0.7066 and 0.6682,respectively.All the parameters indicated a rather high level of genetic diversity of core lines.2.Among the whole set of 84 simple sequence repeats,dinucleotide SSRs could capture more alleles and genetic diversity than other repeat SSRs.3.Clustering results with EUCLIDEAN method based on the genetic diversity of 136 inbred lines that the inbreds can be classified into 4 subgroups,Reid,P,Lancaster and mixed.4.Population structure analysis showed that the inbreds can be classified into 4 subgroups which corresponding to the four main germplasm sources:Reid,P,Tangsipingtou and Lancaster, respectively.And the proportion of each subgroup was 12.50%,16.17%,11.03%and 34.56%.In addition,there were also 35 inbreds which were classified into the mixed subgroup,and the proportion of mixed subgroup was 25.74%.5.A distance based clustering method and a model based clustering method got the same results of the whole set of 136 inbred lines.