Affection of sunflower samples of VIR collection by broomrape (Orobanche сumana Wallr.) and molecular differentiation of plants, having contrasts in resistance

An evaluation of stability of 500 samples of cultivated sunflower of world collection of VIR to high-virulent population of broomrape from Tatsinskiy area of Rostov region was made. Entirely resistant samples were not found, however, they were differentiated to groups with different degree of affection. The samples with distribution of trialed plants for susceptible and entirely resistant ones were defined. PCR-analysis of DNA had shown genetic in-homogeneity of resistant and susceptible plants. The loci, polymorphic for these groups of plants, were defined.