Genetic characterization of some broomrape populations via molecular markers

Orobanche cumana Wallr. (sunflower broomrape) is a parasitic plant that causes huge yield losses in agricultural lands, especially sunflower (Helianthus annuus L.). Genetic characterization studies in O. cumana, which can cause contamination in sunflower fields, are limited. In this thesis, the broomrape plants were grown by using the seeds of the broomrape populations sampled from Edirne, Kırklareli, Tekirdağ, and Adana provinces. The sensitive Özdemirbey sunflower variety was used for growing broomrapes. Eight microsatellite (SSR) loci (Ocum-52, Ocum-70, Ocum-81, Ocum-87, Ocum-108, Ocum-141, Ocum-160, and Ocum-196) were used for genetic characterization and determination of the genetic diversity of broomrape populations. All eight SSR loci used in the study were found to be polymorphic. 22 alleles were observed in 146 samples analyzed. Genetic diversity parameters; Na=2.016 (mean number of alleles per locus), Ne=1.404 (mean effective alleles), I=0.386 (mean Shannon Constant), Ho= 0.199 (mean observed heterozygosity), He=0.241 (mean expected heterozygosity), and PIC =0.199 (mean polymorphic information content) were calculated. As a result of AMOVA (Molecular variance analysis), it was found that the genetic diversity of the populations was 53% within the population. Populations were divided into 2 groups according to the dendrogram created using the UPGMA method and STRUCTURE analysis. Group 1 included AE2003, AD2018, T2018, MT2013, LE2013, and K2019 populations, while group 2 included LK2013 and HT2016 populations. The results we obtained have enabled us to reach important genetic diversity information about the studied populations, and the information obtained will provide important contributions for planned studies in the future.