Objective  To reveal the genetic diversity and relationship of 170 germplasm resources of Gerbera jamesonii Bolus in different populations and types, and provide reference for introduction, protection and utilization of gerbera germplasm resources.

  Method  1-3 pairs of EST-SSR primers with high polymorphism and clear bands were selected for each chromosome pair, and 170 gerbera germplasm DNA from 6 different populations were amplified by PCR. SSR polymorphism, genetic differentiation among different populations, genetic uniformity and UPGMA cluster analysis were used to evaluate the genetic diversity and phylogenetic relationships among different individuals and populations of gerbera.

  Results  A total of 168 alleles (Na) were detected in 39 selected EST-SSR primers, with an average number of 4.308, the average Shannon information index (I) was 1.098, and the variation of polymorphism information content (PIC) was 0.431-0.920, with an average of 0.760, which was higher than 0.5. The total allele number, total genotype number, average allele number, average genotype number, and average heterozygosity were higher in population of China Yunnan and mixed population, the genetic diversity was relatively rich. The genetic distance of the six populations ranged from 0.016 to 0.158, with an average of 0.069, and the genetic consistency ranged from 0.854 to 0.984, with an average of 0.935. The genetic distance between China Yunnan population and mixed population was the smallest, and the genetic distance between German population and Japanese population was the largest. The results of population clustering analysis showed that the German population, China Yunnan population and mixed population were clustered into one group, and the relationship was relatively close. The results of individual clustering showed that 170 germplasm resources were divided into 6 groups (I, II, III, IV, V, and VI) at the genetic similarity coefficient of 0.550. At the genetic similarity coefficient of 0.558, group V could be divided into 4 subgroups, and at the genetic similarity coefficient of 0.570, group VI could be divided into 4 subgroups. The distribution of gerbera with single population origin, including types of potting, pasta, bubble, was relatively simple, while the distribution of other gerbera germplasm was relatively dispersed.

  Conclusion  The EST-SSR markers were highly polymorphic and could be used to analyze the genetic diversity and relatives of gerbera germplasm resources. The genetic diversity of gerbera germplasm resources is rich, and the genetic diversity of different populations is quite different. The results of this study could provide important references for the introduction, protection and breeding utilization of gerbera germplasm resources.