Studying sunflower (Helianthus annuus L.) genetic diversity using RAPD and ISSR techniques

RAPD and ISSR techniques were employed in this research to study the genetic diversity within twenty-nine local and introduced sunflower (Helianthus annuus L.) genotypes. Thirteen primers were used for RAPD, which generated 74 molecular markers, 60 of them were polymorphic. On the other hand, the 24 primer pairs used for ISSR generated 129 molecular markers with only25 polymorphic markers. Percent Disagreement Values (PDVs) between genotypes ranged between 0.01 and 0.27 for RAPD and between 0.01 and 0.07 for ISSR. Combined data revealed PDVs ranging between 0.02 and 0.13. Polymorphic Information Content (PIC) values reached 0.31, with an average of 0.13 and 0.03 for RAPD and ISSR respectively. These results show that ISSR is not suitable for sunflower fingerprinting since it provides low degrees of polymorphism, which makes RAPD more appropriate. Finally, combining different types of markers is necessaryto overcome the problem of monomorphism and for maximum coverage of a genome.