Abstract

Information about the genetic diversity and relationships among breeding lines and varieties is not only useful for germplasm conservation and inbred line identification, but also for the selection of parental lines for quantitative trait loci (QTL) mapping as well as hybrid breeding in crops, including sunflower. In order to develop mapping populations, genetic distances among twenty eight sunflower genotypes were evaluated using simple sequence repeat (SSR) markers. One hundred and two markers were generated by 38 SSR loci and the mean for the number of allele per locus was 2.32. Polymorphism information content (PIC) values ranged from 0.09 (locus ha3555) to 0.62 (locus ORS598) with an average of 0.41. Jaccard's coefficient similarity matrix for the studied sunflower genotypes varied from 0.25 to 0.9 indicating a broad genetic base. The maximum similarity (0.9) was observed between genotypes RT931 and ENSAT-R5, while the lowest similarity (0.25) was between genotypes LC1064C and LR64. Based on unweighted pair group method with arithmetic mean (UPGMA) clustering algorithm, the studied genotypes wereclustered in four groups. However, some genotypes have the same specific characters that influence their clustering, and as a result, the results of the principal coordinate analysis (PCoA) largely corresponded to those obtained through cluster analysis.

Key words: Cluster analysis, genetic diversity, principal coordinate analysis, sunflower, simple sequence repeat.

Abbreviation

SSR, Simple sequence repeat; QTL, quantitative trait loci; PIC,polymorphism information content; PCoA, principal coordinate analysis; RAPD,random amplified polymorphic DNA; RFLP, restriction fragment length polymorphism; RILs, recombinant inbred lines; M, mutant;  BL, breeder lines; SSD,single seed descent; PCR, polymerase chain reaction.