Genetic diversity of wild sunflower (Helianthus sp.) accessions with different tolerance to mid-stalk white rot

Abstract

Random amplified polymorphic DNA (RAPD) markers were used to detect polymorphism among accessions of wild sunflower species Helianthus maximiliani, Helianthus tuberosus, Helianthus mollis and Helianthus rigidus with different tolerance to mid-stalk white rot and selection of potential markers for different levels of tolerance to this disease. Estimates of genetic variation showed that genetic diversity was equally distributed between Helianthus species and within them. Cluster analysis corresponded to the phylogenetic relations within the genus Helianthus. The results obtained by principal coordinates analysis (PCoA), where the first two principal coordinates accounted for 83.7% of total variation, perfectly coincided with the results of cluster analysis. Contingency coefficient significance test showed that most of the used primers generated bands associated with some level of tolerance or susceptibility to midstalk white rot. Furthermore, contingency analysis showed that primer C12 generated bands associated with resistance (100%) to mid-stalk white rot both in H. mollis and in all accessions, while primer X18 generated bands significantly associated with high tolerance (75%) in H. rigidus, H. mollis as well as in all tested accessions. The C15-600 bp locus was found to be significantly associated with high tolerance (75%) in all accessions, and medium tolerance (50%) in H. mollis.