Assessment of genetic diversity among sunflower genotypes using microsatellite markers

Genetic diversity estimation of plant materials is one of the important pre-breeding activities in breeding field crops. Twenty-one microsatellite markers used to assess genetic diversity and relationship of 68 sunflower genotypes (Helianthus annuus L.). All of 21 pairs of SSR (Simple Sequence Repeats) markers produced a total number of 49 polymorphic bands. DNA fragments ranged from 92 to 850 bp. The highest and lowest polymorphic information content (PIC) values were determined as 0.58 and 0.10 for marker Ha806-ar and Ha494-ar. The number of alleles per locus was calculated as 2-6 with the average of 2.86. In this study, CMS (Cytoplasmic Male Sterility) lines showed the highest and Iranian hybrids showed the least polymorphism, respectively. Principal coordinates analysis revealed that Iranian hybrids were well-separated compare to the other groups. The analysis of molecular variance (AMOVA) indicated higher genetic variation within groups (90%) rather than among groups (10%). This study revealed that the SSR markers such as Ha806-ar could be a useful tool for distinguishing sunflowers genotypes. According to the study, there is a significant genetic distance among individuals. Parental lines (R26 and CMS502 lines with lowest similarity coefficient) may be useful for future sunflower crossing and hybrid breeding programs. Generally, high similarity coefficient estimation among investigated sunflower groups revealed that there was a narrow genetic base in investigated materials suggesting broadening its genetic base by introduction of new genes into existing breeding materials.