To increase the genetic diversity of maize inbred lines and accelerate the use of imported elite germplasm resources,122 maize inbred lines from the United States,Serbia and China were subjected to analyze the genetic diversity and the phylogenetic analysis by using SSR molecular markers. A total of 115 alleles was detected by29 polymorphic SSR markers,with an average of 3. 97 alleles per SSR marker and with an average polymorphic information content（ PIC） of 0. 50,suggesting relatively high genetic diversity within this population. The observed heterozygosity（ Ho） was 0. 03 indicating the high genetic stability and homozygosity. Within sub-populations,the allele number（ 3. 55） and Shannon＇s information index（ 0. 93） in the American NSS group were the highest and the number of effective alleles（ 2. 37） in the Serbs group was the highest that suggested higher genetic diversity in groups of American NSS and Serbs,in contrast to the other two groups. The genetic distances among the four groups ranged from0. 1403 to 0. 4695 with being the largest genetic distance between American NSS and Chinese inbred lines and with being relatively smaller（ 0. 1419,0. 1403） between American NSS and American SS or Serbs. The genetic consisten-cy of the four groups ranged from 0. 6253 to 0. 8691. The higher genetic identity among the groups of American NSS,American SS and the Serbs indicated that the genetic exchanges between American and Serbia inbred lines are frequent and their genetic relationship is relatively close. The clustering analysis showed that 122 maize inbred lines could be divided into 9 major groups. Two groups of American SS and NSS were clearly distinguished. The American SS was further divided into 2 subgroups（Ⅰand Ⅸ）. The American NSS was divided into six subgroups（ Ⅱ-Ⅶ）,while the inbred lines from Serbia are dispersed in the NSS groups. Thus,this study provides a molecular basis for better use of maize inbred lines from the United States and Serbia in maize breeding.
Journal of Plant Genetic Resources
Maize (Zea mays L.)