Genetic diversity of sunflower genotypes (Helianthus annuus L.) using TRAP markers

In order to investigate genetic diversity of sunflower genotypes, TRAP markers were used with six fixed and arbitrary primers. Nineteen primer combinations generated a total of 116 bands in which 109 of them were polymorphic. Restorer inbred lines with a mean of 22.76 polymorphic bands had the highest polymorphic loci (84.48 %), and Iranian hybrids with a mean of 2.97 polymorphic bands had the lowest polymorphic loci (40.52 %). Maximum and minimum genetic distances were between restorer lines and Iranian hybrids (0.151) and foreign hybrids and open pollinated cultivars (0.064), respectively. Maximum genetic similarity was between restorer and CMS lines (0.066). AMOVA analysis revealed that 87 % of total variance was within groups, and 13 % was between groups. Using UPGMA method of clustering and principal coordinate analysis, three distinctive groups were identified. Minimum similarity coefficient (0.472) was observed between R42 and CMS328 inbred lines. Results showed that TRAP marker was useful in genetic diversity estimation of sunflower genotypes. Higher similarity coefficient (0.755) for the studied genotypes indicated a narrow genetic base suggesting increasing genetic diversity of sunflower germplasm and selection of high diversity of new inbred lines in the future sunflower breeding programs.