Broomrape (Orobanche cumana Wallr.) is an obligatory parasite which is able to decrease significantly sunflower yields. The race G is the most spread and virulence broomrape race in the Russian Federation. Cultivation of genetically resistance sunflower varieties and hybrids is the most ecologic and economically efficient method to control this parasite plant. Usage of DNA-markers when selecting the resistant plants increases significantly the effectiveness of a breeding process. To mark the sunflower resistance to broomrape race G, using bioinformative approaches, we developed new DNA-markers: four SCAR (sequence characterized amplified region) and ten SSR (simple sequence repeat). These markers were tested on 20 lines and hybrids of sunflower. Due to the results of this testing, all SSR- and two SCAR-markers were eliminated by steps. SCAR-marker RORS1 was characterized with the presence of an amplified DNA fragment with a length ≈ 168 bps and showed association with a trait of resistance, and SORS1 with a fragment length ≈ 322 bps had a relation with a sus-ceptible phenotype. These markers composed a marker system for a multiplex PCR, which allowed distinguishing resistant and susceptible lines and hybrids, except a line VK678 and F1 hybrids developed using this line as parental one. To eliminate faults of the marker system, seven SCAR-markers analogous to SORS1 were created. Due to estimation result, we selected a marker SORS9 characterized with the presence an amplified DNA fragment with a length ≈ 217 bps in susceptible phenotypes. The new system of markers RORS1/SORS9 for a multiplex PCR was validated on 70 sunflower lines and hybrids. The susceptible lines and hybrids were characterized with amplification of only marker SORS9, resistant lines – only marker RORS1, and resistant hybrids – both markers. The developed marker system allowed distinguishing all susceptible lines and hybrids from the resistant sunflower genotypes.

Studying of sunflower lines resistant to broomrape race G, bred in V.S. Pustovoit All-Russian Research Institute of Oil Crops (VNIIMK), Krasnodar showed the genetic control of resistance is monogenic with incomplete dominance. The purpose of the research was to seek and analyze molecular markers for the genes of resistance to broomrape race G using PCRmethods. In our research we used six developed in VNIIMK lines-donors resistant to broomrape race G: RGP1, RGP2, RGB, RGL1, RGL2, RGA, and susceptible lines VK 101, VK 678, VK 680. We extracted DNA from the leaves of young sunflower plants using STAB-buffer. For PCR-analysis we used 17 pairs of primers of two types: SCAR (sequence characterized amplified region) and SSR (simple sequence repeat). Conditions of amplification are as recommended by authors of markers with experimental selection of a temperature for primers hybridization. Within the research we balanced involved into work SSR- and 12 SCAR-loci using BLAST and a set of HanXRQr1.0. Due to these data we composed a physical map of loci location. After assessment of six resistant and three susceptible parental lines, seven markers demonstrated polymorphism by a length of locus DNA and two ones – by presence/absence of amplified fragment. For markers ORS 683 and ORS 1112 we observed a relation between loci polymorphism and susceptibility of parental lines to broomrape. This was certified with a presence of an allele of 364 n.p. length in ORS 683 and an absence of an allele of 375 n.p. length in ORS 1112. These markers were noted as primary ones for hybridological analysis in F1 и F2 with selected pairs for crossing. Additional markers will be selected individually using obtained data on loci polymorphism. Thus, as a result of the research we created a physical map for the further markers selection, found hybrid combinations and markers from the studied ones for hybridological analysis.

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Development and study of recombinant inbred lines of sunflower with different content of oleic acid in seed oil. Ya.N. Demurin, doctor of biology Yu.V. Chebanova, PhD in biology O.M. Borisenko, PhD in biology S.Z. Guchetl, PhD in biology D.L. Savichenko, researcher S.G. Efimenko, PhD in biology O.A. Rubanova, postgraduate student A.A. Shirokikh, Master' degree student V.D. Shamray, schoolgirl

The parasitic plant Orobanche cumana Wallr. is one of the main biotic limiting factors for obtaining high yields of sunflower. Since plant resistance to different broomrape races in different genotypes can be controlled by different genes, to ensure the evaluation of breeding material using DNA markers (MAS), it is necessary to localize the resistance gene for each of the sources. The aim of the research is to find the location of the Or7 gene, which controls the resistance to one of the most virulent broomrape races, on the sunflower linkage map and to determine the DNA markers cosegregating with it. For research we used the lines of breeding of V.S. Pustovoit of All-Russian Research Institute of Oil Crops (VNIIMK) resistant and susceptible to race G of broomrape. We used SSR-primers ORS 683, ORS 1040, ORS 1112, and ORS 202 for the PCR analysis. We excluded the location of the gene in the upper part of LG3 in the immediate proximity to the microsatellite loci ORS 683, ORS 1040, ORS 1112. Based on the studied literary sources and the reference genome of the sunflower HanXRQr2.0-SUNRISE, we compiled a partial physical map of LG3 and determined the area for further search for the localization of the Or7 gene and DNA markers cosegregating with it.